The technical specifications of the Coincidence 5 seem quite suitable for the Atma-Sphere MA-2 amplifiers:
I must be missing something in a big way to not understand why you describe these speakers as "unfriendly." I'd encourage you to contact Ralph Karsten at Atma-Sphere to confirm, but on the surface it seems to me that the MA-2 amps would have no trouble driving these speakers. If that's indeed the case, the Atma-Sphere MA-2 would be a no-brainer choice for me.
Disclaimer: Atma-Sphere MA-2 owner
"phase correct, 6 dB per octave first-order crossover network"
Impedance, Nominal: 4 ohms
Impedance, (20-200 Hz): 4.6 - 9.2 ohms
Impedance, (200-20 kHz): 5.0 - 7.7 ohms
http://www.dynaudiousa.com/products/archive/conf5/conf5spec.htm
I must be missing something in a big way to not understand why you describe these speakers as "unfriendly." I'd encourage you to contact Ralph Karsten at Atma-Sphere to confirm, but on the surface it seems to me that the MA-2 amps would have no trouble driving these speakers. If that's indeed the case, the Atma-Sphere MA-2 would be a no-brainer choice for me.
Disclaimer: Atma-Sphere MA-2 owner