Thiel 3.6, what will drive them best?

You'll be happy with the McCormack DNA1 or the Classe 201.
I'd negotiate the best price you can and you'll be happy with the resulting performance of the 3.6's

I have heard the 3.6s sound good with both of these amps.
Ayre V-5XE
Pass Labs X150
These would be the lower level of amps (power and quality)I would use with the 3.6s. I liked the Ayre better than the Pass. Both are a little above your range but in the long (and short) run you will be better off.
IMO nothing drives the Thiels like the big Krell amps.

I'm driving my 3.6's with a pair of Jeff Rowland 201 monoblocks, and I'm very happy with the combination.

Good luck!

I had 7BSTs for a time with a pair of CS7s. This sounded good for a couple of years. The key is not to crank it to loudly, I did one day and blew out the high end driver in the coaxial high/high mid unit (which Thiel replaced free of charge). The Brystons just didn't have the current delivery capacity to avoid going squarewave at high levels.

As long as you don't have unrealistic loudness expectations, the Brystons will do just fine.

You see...the last post (Stevecham) is the exact point a number of us have been making.
Even an amp as fine as the bryston 7bst is unable to deliver enough current for the Thiels.
A high current delivery amplifier is an absolute must.