You want HEAVY?

Scout out an early-to-mid-70's Ampeg VT-22. It's a 120 Watt 2x12" combo with a clean sound that kills! Add a distortion pedal, and the Voice of God becomes The Doombringer.

They crop up on eBay fairly often for about $400 US. Retube it with JJ KT88 power tubes and fresh preamp tubes (don't waste your money on that Garbage Tubes crap), and you have the best possible amp for way under a grand!

The V-4 (head version) or the V-4B (bass head without reverb) are even less expensive.