Try Buddas, THDs, all that gear 'shredders' usually shun. You might find very cool tones. And if gain is an issue, you can always slam a good dist/boost pedal in the signal path to get things a bit nastier.
Get an amp which gets out the sound of your guitar, not an amp that always sounds like that amp, if you know what I'm saying.
I've noticed that stuff that really work and sound great don't have all the knobs and bells & whistles in the world, so don't judge an amp because they look simple. The just might very reactive to your touch and other gear thus providing lots of sounds.
Check out
www.custom-sounds.com they have lotsa rap about high-endish gear.
