There are many great amps that will drive your Coherent speakers well. I had a pair of Coherent 8s for years and finally settled on an EL-34 amp and 4P1L preamp by Raul Tarta. Made in CT (as I recall). I know, you prefer an integrated solution but these are great, unsung products and a great value. Made in the USA. Simple Pleasure Tube Amps
I'm surprised that no one has mentioned Decware. Steve Deckert is a legend in the (mostly off Audiogon) audio community and he offers several integrated amps, of different configurations. FYI I believe that all of the Decware amps use a passive preamp section. But they are very well made, sound great and seem to retain phenomenal resale value.