I use the Atmasphere MA2 mk2.3's with the MAXX2's and can attest that the combination is everything that I had been hoping for in 2-channel music reproduction.
I have friends that own the MAXX2's and use them with either the Lamm ML2's (18w) or the new Audio Research 610T's. There are likely a number of different amps that will match well with the MAXX2's, however, the best bet would obviously be to try several before deciding what works best for you.