Monos for Quad 989

I'm getting a deal on a pr.of Quad 989s and thought that with the savings, I would increase my investment in amplification. I plan on going mono blocks and my research to date has me narrowing the choices to: Audio Research VM220, Audio Research VS110, Atma-Sphere MA-1 mkii3, or V4 Quick Silver. I am not able to easily preview any of these monos and before I make an investment, I'd like to get feedback from Quad owners who have any of these amps and/or owners of these amps. I'm most interested in your comments about sound, reliability, heat (no kids in the house but we do have a dog), customer service, etc. By the way, I have been a solid state owner for a long time but am looking forward to making the switch to tubes but know nothing about upkeep,etc. Also I am looking to purchase something that will last for years--maybe the last amp I will ever buy!!!