Best Amp for Magnepan 1.7?

What would be the best amp out of the following four brands to power the new 1.7s? Also, would a monoblock setup be worth the extra money? I like McIntosh; however, I'm not sure if the detail and speed will be up to what the 1.7 would want.

Krell
Mark Levinson
McIntosh
Bryston

Thanks guys