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

" Well, you're talking about making some major changes in both electronics and speakers. This seems unlikely to yield the best results."
If you don't change something in the system there won't be any results, good or bad.

" I'm a big fan of subwoofers. They offer advantages that no floor standing speaker can -- placement options. However, the Vandersteen subwoofer approach has several constraints. There are constraints on the electronics when using the Vandy system. There are placement constraints of the sub(s) when using the Vandy system. There are constraints on the bass performance of the main speakers when using the Vandy system. The Vandy sub design is specifically designed for Vandy speakers -- the constraints of using first order filters."

That's not even close to being true, and you know it. Show me where it says Vandersteen subs are specifically designed for Vandy speakers. The owners manual clearly states you can use the subs with a wide variety of products besides as well.

As for placement and first order concerns, its just the opposite. The real issue here is that you have an Ax to grind with Vandersteen. I've read some of your other posts where you were arguing with John from AC, and some of the others. You were trying to push your version of the facts, and got upset when you were proven wrong. Now, every time I see you comment on Vandersteen products, its always negative combines with false info.

I'm sure when you read this, you'll have no idea what I'm talking about. 

Being a Vandy fanboy, I am hardly impartial, but I, too, would opt to keep the 1ce's and get a pair of 2w or 2wq's in a perfect world (though you would need a pair of M5-HP crossovers or a pair of fixed crossovers matched to your amp).
REL is a good alternative, so is HSU, and they are very reasonably priced.-maybe a temporary fix until you can get a pair of Vandy subs.
John Rutan of Audioconnection would be a great guy to get honest information regarding the upgrades you are considering. 
PM him, his Agon ID is Audioconnection.
B

Thank you to everybody who has weighed in. @sfall, didn't mean to start any conflicts lol. It's nice getting the reassurance that the Vandersteen's are a great speaker. I certainly have been thrilled with certain aspects of clarity and presence.  But I have known since I bought them that they lacked lower bass detail with my receiver (which initially was for dual HT, and two channel listening. I mainly listen to records through the system to ratio of about 90% records, 10% movies) And now realize that going exclusively two channel is more appropriate for my enjoyment. I mainly listen to post punk, rock, and blues, but as most Audiophile records are made for 50+ year olds by 50+ year olds( I know mofi has a bit of a wider breath). I now have a nice collection of jazz, and blues vinyl that sounds great! Anyhow, sounds like I need to audition the Rogue with my Vandy's first, and then the Revel Concerta F36's  with my NAD, and lastly a sub with my Vandy's and NAD, I've never auditioned any equipment, so not 100% sure how it works, but have read Robert Harley's guide, and there's an explanation of the process. I will say that I do trust my dealer Rick from Brooks Berdan, and know he'll be great council here, but it's always nice to get consensus outside of the shop. I appreciate you all!

Have no experience with the Revel you speak of so take my comments with a grain of salt
The ones are amazing.....the last pair I heard (I) driven by a Marantz receiver with a Bluesound Vault server/ DAC were glorious...( about an hour south of Monrovia.... hint)
but hey I am biased as a many model Vandersteen owner...
your dealer is solid but is not going to steer you towards Vandersteen- they have not carried them for many years.
Upgrade the amp with an eye to future... as others have said there are a number of excellent tube and SS integrated amps out there and affordable. Richard engineers for an easy load and also answers the phone.
you should be able to get a demo amp from any number of great so cal audio retailers.

Also
please point me to a good sounding post punk album....