Suggestions for power amps

Why aren't you looking at Buckeye Purifis? Seems like an easy choice. 

   + 1 for adding sub(s). Then roll in an amp. I run low power tubes to Zu’s , but rotate a 50 wpc SS amp. I back the subs off a tiny bit when going to SS. BTW , I loaned some tubes to a fellow for his pre. He has the same amp as you and loves it. Happy Hunting , Mike B. Oh, and + 1 for the Pass. 

The Benchmark ABH is an excellent amplifier; I used it with my Fyne Audio F-702 speakers and got wonderful sound.  I sought a bit more power, however, and am now using two mono bloc Odyssey Kismet power amplifiers, which put out about 200 watts each, and the sound is wonderful.  Excellent imaging, great tonal qualities for the instruments, and dead silent background.

@mike4597 You could have bought another Benchmark and ran them in monoblock mode and that would have given you over 300 watts per channel.

In your price range, the Kinki Studio monoblock amps at $3700 have enormous power and recommended in a review as comparable to low $10Ks amps.  Todd at Tekaudiospecialties.com is the U.S. distributor, does modifications to make them even better and is a very knowledgeable audio electrical engineer (many decades of computer work).  I just purchased a SOTA CD transport from him (Jay's Audio cdt3 Mk3).  I'm looking to purchase a 10X more expensive amp (Westminster Labs REI monoblocks).  For the price, it could be what you are looking for.