As I've said in the past, I use a pair of Cambridge 840s with my 3.7s and I think they're completely adequate, at least at the moderate volumes I listen at. You'd pay in the 3-4k range for a pair. I know a guy who hangs around on audioasylum uses a $2,500 parasound a21 on his 3.7s and has for a while. I tend to think that amps are a good place to make a compromise on price. As long as they have enough power the differences tend to be small compared to speakers. I think the preamp makes a significantly bigger difference overall. The Benchmark looks like it'd probably do fine with most Thiels, although it's pretty small compared to your pair of Classe amps. I'd be interested to know how a bridged pair would do with the low impedance.
I assume going forward people building Thiel systems will be the type who are more interested in getting great sound for the money than in big names or eye candy. I get more satisfaction from knowing I got great performance for a moderate amount of money I've got around 16k in my system and it's so good I have no interest in messing with it. Benchmark DAC2, Bryston BP26, Cambridge 840 x2, Thiel 3.7, Infinity Intermezzo 1.2 sub. The electronics definitely won't win a beauty contest but they perform great.
I assume going forward people building Thiel systems will be the type who are more interested in getting great sound for the money than in big names or eye candy. I get more satisfaction from knowing I got great performance for a moderate amount of money I've got around 16k in my system and it's so good I have no interest in messing with it. Benchmark DAC2, Bryston BP26, Cambridge 840 x2, Thiel 3.7, Infinity Intermezzo 1.2 sub. The electronics definitely won't win a beauty contest but they perform great.