I'm on a quest for an affordable amp for a pair of Martin Logan reQuests. I'd like to pick up a used adcom GFA555 or two for bi-amp. Or a rotel 1080 new. I've heard MLs are hard to drive due to their planar nature and low impedance/high voltage (instead of the current needed for dynamic speakers). Anybody have any ideas? I'd like to keep costs below 1000 and good power of 150 watts or more. This model speaker dips to 1.2 ohms in the very upper frequency range. For some reason people don't seem to like adcom paired with electrostats.