see if you can get a used pair of Levinson 33H monoblocks. You may be able to fit in your budget and these are just excellent amps. McIntosh MC501 monoblocks are nice too.
I have a Pass Labs X250.5 that kicks butt on Zeppelin, Metallica, Floyd or whatever else you throw at it. You have to remember one thing though, that heavy metal CDs for the most part are not recorded to be played back on a system like yours, so it may show some shortcomings of bad recordings. Just so you know and are ready......
