Help building first tube system.

I am looking to build my first tube system. Small 15 x 15 room, want stand mounted speakers, cd transport, dac and network player, and tube amp/preamp. Would like to stay under $20,000. Not sure where to start?  No dealers around me for demo or help. Any advice helps! Thanks.
That's just about the perfect budget for a Raven or Prima Luna integrated. Don't bother with separates. You can't come close to the performance of either of those for anywhere near the same money with separates.

35 or so tube watts is plenty, especially with really smart speakers like Tekton Maob that are also right in your budget's sweet spot.

$3k Swarm subwoofer system, of course.

You would also be smart to skip the DAC/trans and go with CD for the same reason as the integrated is better over separates. Actually you would be smart to go with records but that's another one altogether. Whatever. Point is a solid $3k for source and you still have a healthy roughly $6k for speaker cables, interconnect, power cords, Fuses, ECT, HFT, Total Contact and Omega Mats. 

btw yes I know you said "small 15x15" and "want stand mounted speakers" but I assume that's based on the false assumption that's the way to go in your "small" room. Which is simply not true. Stick the above system in there. When you scrape your jaw up off the floor call and let me know.
I'd second millercarbon's suggestion of a Raven Audio integrated. My Blackhawk LE is the most satisfying piece of equipment I've owned in a lifetime of gear changes. The 45-day in-home, no obligation, free trial makes it an easy call, as well. And the customer service from owner Dave Thomson is wonderful.

For tubes, Atmasphere- MA-60 with an MP-3 or UV-1.
Vandersteen VLR's
Rega Apollo CD player
Bluesound Node
Ayre Codex DAC.
If you buy used, you should have enough for good AQ cables and maybe a Vandy Sub 3. Though if you splurge on the AQ William Tell speaker cables, you probably won't need a sub.- And, I heard em.
You could save a bit if you went SS and just got a Belles Aria integrated amp. (That's what was connected to the above mentioned speakers/ DAC/Streamer when I heard those William Tell's connected.
Truly a WTF moment.

How tall are the ceilings? $20 K deserves some travel to a metro area with a few dealers to get an idea on speakers FIRST.

Naim Uniti Core music server $3,000, Audio Mirror DAC $2,500, Manley Jumbo Shrimp preamp $4,600, ATC SCM20ASL Pro mk2 $5,500.  Balance for ICs, PCs, stands, etc.  I believe the Naim doubles as a network player.  Speakers are active, so no amp needed.

This system would be terrifyingly good.  Obviously, everything here is at full retail.  Best of luck building your dream.
That system leaves $4600 for 4 power cords, 4 interconnects, and 1 pr speaker cables. That's an average of only $500 each, with nothing left over for Cones or even any room treatment. The only thing terrifying is the lack of awareness of the importance of everything left out.

For a first system in a small room you might consider something like a Decaware amp and Omega speakers or other high efficiency speaker. For sources just do a little research on CD players, streamers, dacs as there are a lot of them. I use a fairly inexpensive NAD CD player connected to a Benchmark DAC3B and a Node2i connected to the same. Ignore the nonsense about magic mats, fuses, contact pastes and other dubious tweaks and stick to the main components. Once you're  done that reasearch room treatments  and speaker positioning and how it can offer you best sound improvement.  You also don’t need to spend a fortune on wires some research there will go a long way too. Good luck.
Hi Walstib, I think Tomic has it right. Start with the speakers. You really have to go listen. Would you buy a car without looking and driving first?
The speakers will 95% determine the sound of the system. Stand mounts are fine but you may want to consider subwoofers with them as none of them go very low. Everything else? I think build quality and durability are of first importance and I would stick with well established companies with good reputations like Audio Research, Macintosh, Atma Sphere and Manley. You should probably spend 10 K on speakers and 10 K on everything else.

At your budget I would steer you away from some of the "pedestrian" brands of tubed electronics like: Prima Luna, Schiit, Rogue and a few others that I cant recall. These are not bad products, just not nearly as good as others that cost a bit more. Within your budget you can easily afford separates which will always outperform an integrated. I would put as much money into the components and speakers as you can and then upgrade cables and other tweaks (be careful!) as your budget allows. Fundamental from day one are good acoustic treatments for your room. To suggest almost one third of your initial budget on cables and tweaks is absurd and bad advice IMO. I have limited experience with Atma-sphere preamps but the amps are among the best I have heard given the right speaker impedance. 
your 20K budget is more than sufficient to build something nice. Many of us choose amplification or speakers first and go from there. Good advice I've seen in this thread is "buy the best speakers you can afford." I have  a 20K system and half was spent on the loudspeakers.
Thanks to all who have replied.

The room has 10’ ceilings. Walls are drywall but ceiling is wood. Basement room, concrete slab with pad and carpet. 
Intrigued by the Raven line up of integrated tube amps. Anyone else have input on these? What about Cary?  
I guess I should ask the question, any recommendations on a reputable tube amp dealer in Chicago? Couple hour drive but probably the best starting point.

Thanks again and keep the advice coming!
To your question about Cary, I owned two Cary amplifiers, an AES/Cary AE-25 and a Cary Sli-80 F1. I was very happy with both but replaced the Sli-80 with my Raven Audio Blackhawk LE. Cary was started by Dennis Had and he was responsible for how highly regarded Cary gear has been. He still builds and sells amps under the Inspire brand but is no longer affiliated with Cary. Here's a discussion from a couple of years ago about the company and its products that may be helpful.
My budget was similar to yours, although I started with a smaller budget but then had to adjust upwards when I fell in love with a set of speakers.

For my $22k main rig, I put $10k in speakers/sub, $6k in integrated amp, $2k in source/dac/streamer (all in one), $1k in power conditioner, and $3k in everything else (power cables, speaker cables, interconnects, isolation, noise suppression, etc.).

FWIW, that’s what worked for me. Many might say I underspent on source to detriment of others but the only source I use is Tidal streaming (no vinyl, no cds, no digital storage) -- obviously if you care about those things then would have to skimp on some of the categories I went heavier on to fit them in.

Agree with what others have said on auditioning stuff. Try to make it happen. $20k too large a budget not to be quite confident you’ll like what you get. In-home always best but not realistic for many. I did all of my auditioning in dealer showrooms, probably 20+ speakers and 5-10 amps/electronics over a 6 month period. Research was well worth it, as none of the pieces I ended up purchasing would have even been on my short list when I started.

Sorry I don’t have tube recommendations for you, but I think listen to as many speakers as you can with tube amps and it’ll become clear to you. You’ll know when you hear it. Also suggest don’t foreclose on floorstanding speakers -- be sure to compare some of them against the bookshelves you’d otherwise get. My experience was that, even with standmounts and a sub, the sound of floorstanders was just so much fuller and with additional layers than the bookshelves could deliver.  I like bass so I got the sub anyway, haha. YMMV