For my first post on the Klipsch forums I am going to offer an opinion on driving the Chorus 1's.
I have owned a pair of Chorus 2’s since the mid 90’s. Initially I used a Carver M1.5t power amp (allegedly 350 WPC). The result was loud, lots of bass, and not so much imaging. I relocated to a smaller space, inherited some new equipment, and decided to try a B&K power amp (105 WPS) with the CH 2's. Sound was good, balanced, just not so loud. After another relocation I purchased a Crown XLS 2002 (375 WPC, class D) for use in a bi-amp system (not the Chorus 2’s). After a month I decided to try the Crown with the Chorus 2’s and wow… I have got plenty of volume, plenty of bass (not muddy), crisp highs and imaging. I have heard instruments on some of my CD’s that I don’t recall hearing before.
So, my suggestion for driving the Chorus 1's would be min 200 WPC, and consider a class D amp.