Amplifier for Martin Logan Requests

I currently own a pair of Martin Logan Requests with An Audble Illusions pre-amp. I have auditioned the Calyton Audio M70 monoblocks and they sound good. The only problem is when I play them at high volumes they lose control. I have heard about Bat VK 200 & 500 , Sim Audio W-5 and several tube amps as better alternatives. I would appreciate any comments from ML owners and those who are familiar with these speakers. Thanks