Used amp recommendation

VT 100 MKII great amp as well and I've heard the MKI and II but not the MKIII. The 100.2 was a solid state amp. The VT 100 MKII is a bear to re-tube and bias.  I'd still go with a 100.2 regardless of the maintenance and cost of the tubes on the VT 100. My father has a VT 50 which is a great amp as well; less power obviously but similar in sound. It's just what one prefers... again both great amps but the 100.2 will be less money, no tube cost but might be harder to find for good reason. Good luck finding a VT50 as well.

Audio Research 100.2. Owned one and it is a great amp. I know the Aragon amps well and Monitor Audio speakers. Not saying the Aragon aren't nice amps; worked at a shop years ago that sold them. For your budget and the speakers you have, I think you can do better. Parasound A23 or a used A21 would be a great amp as well and I have heard both on Monitor Audio's. The 100.2 is a killer amp and I probably should have kept mine.