Add a Subwoofer to my Vandersteen 1ce s or replace with Revel Concerta2 F36

Interesting thread.  Fan boy here too.  Quatro's shipping in a few days.  Very familiar with all the speakers mentioned here.  I can tell you that if you like the Vandersteen's mids and highs, that once home and over time, you will be looking for a new set of speakers if you don't stay with the 1's or get a pair of the 2's.  The Revel's are fine speakers, but they can be tipped up at times.  Personally, (My ears) I find them fatiguing over time.  
The amp has to change obviously.  What is your budget?  Can you afford a 1800 integrated amp?  Can you afford a new pair of 2c's (he has made so many upgrades with new materials, I think a new pair is going to make him much happier IF he can go that route).

Personally, I would get a new pair of 2c's (go see Randy near the Santa Monica Pier.  I think it's third street.  We are all free agents and just because we love a dealer, doesn't mean you stay there if they aren't selling something you really want.  I always go visit dealers around the country and I often purchase new items from them. I use Audio Connections for most things as he usually has what I want.  Randy can get you into a pair of new 2's and pair you with an inexpensive integrated that will make you much happier for now and then you can upgrade the amp as you are able to.  That said, the new Belles integrated is beautiful with all speakers I've heard them on from ProAcs to VAndersteens.  I still love the NAD integrated amps with 2's.  If you get the large one, it has plenty of power for the bass and it has control that you need and want.  

Even though I had the Treo's for a couple of years, I still auditioned everything under the sun before getting the Quatro's.  I still go audition everything I can so that I know what's out there and what I like and don't like.  If I do find a speaker I like better than the Quatro's for the same price or less, I'll make a switch.  So far nothing I've heard comes close.  Folks don't truly realize how detailed his speakers are until they DON'T have them in their system.  It's the old you don't know what you have until it's gone.  That's why I don't think you'll be happy with the Revels.

JMHO Pete

Agree with jafant.  Listen to the subtle dynamics. Listen to the sibilance (John Mellencamp stuff is good here).  Listen not just to amount of bass, but also the quality of each note.  Which gives you a real sound stage.  Does the sound stage stay big all the time or does it change per recording?  I'd listen to well recorded music to see which one is better and then to other stuff you just love. 

It will be very hard to make a decision without have them in your own house side by side and all but make some notes and listen to the same recordings.  Get to know the cymbals and piano and then male and female voice etc...  Where are you sitting in the hall....I never understood components that put you IN with the band or orchestra, lol.  

Have fun with it all and listen as a system to make sure it's what you can get out of your own.  Also listen with top of the line components to see how much better your speakers can sound as you upgrade in the future.  Keep us posted.  Two speakers you list are a good start for sure.

I think that 2c is a great speaker.  Personally, I wouldn't buy a pair  that was more than a year old.  I'd ask when they were produced.  Richard makes changes, like many top manufacturer's do and doesn't say anything about it.  It may just be changing a crossover point to warm up the mids, or changing components to a better one that they are able to buy in enough bulk to make it cost effective.  Lot's of little things they can do.  

I've sold and purchased gear used.  I know Bob bought my speakers, but he also came over to see and listen.  Speakers are funny as are transports and turntables.  IF you know the person you are buying from or can go see them before making the purchase, then that's great, but if you can't, I'd just be vary wary and make sure you read a person's feedback.  I've seen too many speakers, including demo's at some dealers (all lines of speakers) not in the shape they look like.  I worry about the socks as someone said above.  IF not careful, they can snag.  I also like to have a warrantee on a speaker.  IF  you can afford new, personally, I'd go that route if possible as warrantees are not transferable with Vandy's.  

Glad you love them.  Keep us posted on it all.  

Where do you live?  Who is the local Vandersteen dealer.  

Glad to hear you are happy.  As you see, the amps are a huge part of the equation.  That little Vandy doesn't get the press it deserves. It's upside is outstanding. That said, the brand new 2's are in a different league. I have a friend who has a pair that he pairs with an Ayre AX5/20 like I use and he said that it sound better to him than any speaker he's heard under 4k with the same integrated.  I heard a dealer drop a pair of the 2c's into his ref system or all AR ref gear and I was blown away.  Speakers have a max point obviously, but when you get a speaker that has no smearing or box colorations, it's amazing how high a ceiling it has.  I say enjoy your 'new' 1's and audition as many speakers as you can.  You'll know when's it right to make a move.

Thanks for the link Johnny.

Fully understand.  Get what you can afford and love them.  The differences are not as huge as some make them out to be.  I'd be very happy with any of the Vandersteen speakers with good electronics.  

Not protesting at all.  I do buy into 4 subs being better than 2 for any bass problems, but the EQ that Richard uses is special and that's one reason we love the Quatro's (well some of us).  It all depends on the room I think.  My Treo's weren't CT's, so the Quatro upgrade made sense, plus my wife would never have said 'oh sure, you SHOULD have two more large boxes in the room", lol.....  

I will say that adding two of the 2w's to any speaker may be the best quality bass you can buy under 10k.  It's not the deepest or earth shattering bass that some of the boxes make, but it's moves a ton of air still and has the best quality of bass I've heard anywhere near it's price range.  To add that bass to a pair of 2's.....wow.

That's why I'd do