Getting my tax return will leave me with about $450 to spend, time to treat myself to some long overdue gear. I'd like to hear some thoughts on which heads you can get into for $400-$650 dollars used, figuring I'll come up w/the difference on my own

. I'm looking for something that I can use to play hardrock and metal, MUST HAVE A LOT OF CRUNCH WITHOUT/BEFORE USING A PEDAL OR PREAMP. Nothing wrong with cheaper either, as long as it's quality. Preferably tube, but nothing wrong with solid state either. I know I don't want a digital modeling amp like a Line 6, I'd rather get a POD and play through the PC if I were going to go that route. I've heard good things about the old Randall RG100ES heads. I've also heard good things about the Peavey 5150 and 5150 II heads and also that they can be had for $500-$600 dollars, but have also heard negative things about Peaveys as well (maybe that was Crate I'm thinking of). Any thoughts, input, or advice would be great, thanks.
Nathaniel
Forgot to mention that I'd like have as much power in the head as possible, 50 watts a minimum, preferably more, say 100 watts.