Help designing a home theater/listening room

I am in the process of designing a home theater with an emphasis on a listening room. The media room space is 15 feet wide by 20 feet deep and the walls will be soundproofed. I am willing to spend around 30-40k for all the equipment and install. Wanted to get peoples thoughts on what would be a great system. So far I was thinking.

Power. Considering krell amp and preamp vs marantz amp/preamp vs Cambridge audio integrated amp

speakers. I liked the Elac black edition floor standing speakers or b&w and will get the matching center and surround speakers. For a 7.1 system.

Subwoofer - undecided on this but considering a genesis subwoofer.

Video. Probably 110 inch screen and jc projector for about 7500 total

Blue ray/Sacd player - oppo

any advice appreciated.
With that budget I would visit a few high end audio professionals and listen to some of the rooms they have set up to get a taste for what you might like. They will help with the system synergy and all the details that will make you satisfied.
Why would you go for an integrated if it will be used for home theater?
Why would you go for an integrated?
Because HT receivers and processors don't do very well making music!
My Onkyo TX-SR876 is wonderful with Blu-Ray movies but
try to play SACD or Cds and the air comes right out of the balloon (no foolin').
Using a quality integrated for the L/R channels makes lots of sense.
All the best on your endeavor. For your budget in less you are a real do it yourself type guy, call in the pro.

Gear wise the most important IMO outside of sound is ease of use. Brands like NAD and McIntosh have a great ease of use factor. If you and the family can't use it easily it sits and gathers dust. You will appreciate a system that other family members don't have to call you in just to play a kids dvd or just to watch regular television. Of the brands you listed, I would stay away from Cambridge Audio. Great sound but not reliable in my experience.

Running a dedicated stereo with HT bypass system would be my choice. But surround sound is not that important too me. The balk of my funds would go to the stereo components and primary speakers. A good center channel but the rears and sides much less important.

It is fun and easy to spend other people's money, so above all let your ears be the judge. Good luck and post your results.
The most important investment you can do in your new room is proper acoustic design. I recommend Jeff Hedgeback, have had the pleasure of supplying equipment to a few rooms Jeff designed, there's even one here on AG. Do not underestimate the importance of a properly designed room.

Best of luck

As an adjunct to Peter's comment, sound "proofed" does not necessarily mean sound "good." Before you do anything to your room I'd recommend you read Earl Geddes' "Premium Home Theater." It will give you a great understanding of what (and what NOT) to do to get a great sounding room if you're not already an expert in this area. I ordered several books on the subject and this one is by far the most user-friendly and useful (at least for me with my limited knowledge on the subject) and will give you a good understanding of both theory and practice. Even if you use a professional I think it's a good idea to have a good foundation in all the options so you can make well-informed choices.

As far as equipment, if 2-channel is important I'd go for a stereo integrated or separate stereo amp/pre and then add the best pre/pro or receiver (which could also be used to power the center and/or rear channels) you can afford to handle HT processing duties and that can be bypassed completely for stereo listening (this is easy to do). Reason is, the number of truly good pre/pros (or multichannel amps for that matter) that can deliver audiophile level sound is very low and they can also be very expensive. What are the odds one of the few high-end pre/pros or multichannel amps deliver optimal sound quality with your speakers and/or for your particular tastes? Going with an integrated or separates gives you a ton more choices and could sound better and actually cost less depending on what you choose. Just food for thought. Hope it helps and best of luck with your project.
You are in need of professional help, and that begins with a room evaluation, and best to do that before you spend a dime. The room, and its treatment, is everything, for it that which you will 'hear'. So find a person, professional acoustician, who can help with that first. Otherwise, you will fall to dealer, much like a used car salesperson, selling you whats on the 'lot'. While you are waiting, check out Toole's book on Sound Reproduction, a classic/bible on better listening. Hopefully an Amazon Drone can put it on your door step in the next half hour.
I'd agree that room design is job one. One hint that worked for me:

Avoid parallel surfaces.

Stepped drop ceiling treatments and/or a platform under the rear row(s) of seats are great for the floor/ceiling issues and pilasters housing lighting elements and/or side speakers are a cool way to break up side walls.

I also used a fabric over acoustic tile wainscoting on the side walls to really good effect.

One thought on amplification - if you intend to do your music listening with the subwoofers in-line, I'd stick with quality HT electronics. I use Integra, but your budget might accommodate Theta. IME, the bass management capabilities found in most quality HT electronics will provide wonderful subwoofer integration in a way that quality analog gear will not. If you listen to music without subs (and/or you use a lot of vinyl) then traditional electronics might (or might not) be a better choice for you.

Just IME and MHO.