Amp for Revel Gems

Odyssey Stratos?
http://www.odysseyaudio.com/products-stratos-mono.html

Trying to find a $50K investment that appreciates in value is no easy thing these days, so why not enjoy it on the way down :)

OTOH, I see a pair of Theta Citadels offered right now on Agon for $6895, which I expect would work very well, though they are a little over your budget.

Mark Levinson or Jeff Rowland, and of course higher-level McIntosh solid state amps all seem like good ideas as well. McIntosh and Revel seem to play well together.

Audio Research D400 MKII ??????

I highly recommend the new Mark Levinson 500H series amps. That's what I own powering my Revels.