Adam gave you a real world answer and if you choose to get an amp, I highly suggest the
Emotiva XPA-5. 200 watts EASY, and loads more into 4 OHM's. Excellent build quality, powerful, only $799.00. Adam has Emotiva amps, I have an Emotiva prepro and 7 channel amp (5 in use), and guys all over the forums have Emotiva because they truely rock out. Great stuff.
Try your system first! If at high volume levels you think its giving out of gas, give that XPA-5 a thirty day try. Yeah they let you try it out for a month, no questions asked.
Just to be fair,
Outlaw Audio sells some rather nice equipment too. There are others, but other members will have to suggest them. Oh yeah, NAD, and Denon come to mind. NAD is the brute force in amps, they build stuff that laughs at 2 OHM loads. I own an old 2 channel NAD 2200 amp that puts out 100 watts per channel into 8 Ohms, and 600 watts into 2 Ohms.
But really try what you've got first. Then do your amp research.
Ric
PS - Check this out:
Nad Home Theater Amps