"Look for a high-current amp. Harman/Kardon, Parasound, NAD would all fit the bill. And the Emotivas will surprise you, they are one of the best values in the market today...
-RW-"
Harmon/Kardon - high current, yes, reliability lately kinda shakey.
Parasound - definitely.
NAD - for rock, not sure that is the ticket compared to these others. Not because they sound "bad", but perhaps because they sound too well rounded and "natural" - better all arounder for many music types, but without the slam of some of these others listed here.
Emotiva - no experience with this product... although it looks VERY intriguing.