Recommend a SS amp for my new Vandersteen Quatro CT

Ayre or Aesthetix will bring you joy!

You are in for a real treat :-)
IMO either amp you own excellent place to start - just make sure to properly adjust Low Pass filter DIP switches when changing amps. !!!!!
i have heard Quatro CT at many dealers across USA  with Ayre, Aesthetix, Rogue, ARC ( Ref 150, HD220 ) as well as VTL. frankly all were outstanding - I have also had a REF 75 at home running my 7 mk2 and can attest that it is one sweet amp !!!
i have an Ayre VX--R Twenty, you might give that a try - I think Richard and Charlie are pretty aligned on many design considerations and philosophy. 
importanly the Filters are RCA or balanced but not both so plan ahead there.
the Aesthetix amp has built in filter should you go that route.
where are you located ?

Sounds like the new Belles Aria preamp and monoblock power amps are also a good match for the new Vandersteens.

I have heard 5a with Quicksiler and can attest they are quite good.
i believe the demo system at CES this year had Brinkmann powered Quatros - said to have been lovely !!!

Once I get my MP3, I will be driving Treo's with Atma-Sphere MA-1's.
I never had tubes before, so wish me luck.
I am currently using a McCormack DNA-1 with gold revisions. When Steve finishes with CES, I hope to have him modify another DNA-1 so I can get monoblocks. 
Then we will have a shoot out.

Many Vandy owners also swear by Ayre.
To be fair, any decent quality amp should be able to power the Vandy's. Your source and preamp would probably contribute more to sound differences.