The Adcom 555 is a good choice of course a McIntosh amp (McIntosh 2300, my choice if it were me) would be the ultimate. I sold the Infinity Quantum Series speakers and we used 270 to 300 watt amps to run them. We had two pairs of the next to the top of the line Quantum 2's & 3's. Played a track from a Boston LP organ music and they thought the electrical transformers in the building were going. Sound was phenomenal, huge amount of clean bass. These should give you plenty of bass and sweet, sweet mid & highs as you have found out. Nothing like the big speakers of the 70's and early 80's. Great that the wife appreciates them.
Check out his site as it has great information on the Emit tweeters and L-Emin mid drivers.
BobbyShred's Vintage Infinity Speaker Page
Here is a picture of my score from a few years ago JBL 4343 Studio monitors just about completely restored. Not my picture but the exact speakers. Only 175lbs each and they need a lot of power as well.
