one place I can recommend is http://www.musicyo.com, my brother bought a quad rail kramer explorer from there, he got it very cheap, but it's a sweet guitar (it DID need some slight setup alterations and a small bit of fret stoning) but for the price he paid, a couple of hours work on it was well worth the cash he saved!
I've played on most guitar brands, they all have good and bad models and guitars suitable for different types of music, but think of the general guidelines
PRS - expensive (VERY!) but classy, very rich sound, slightly more 'trim' than a les paul
Les paul - Huge variety of sounds, nice short scale length (makes string bending more easy)
Telecaster and Stratocaster - incisive and cutting sound, often have lots of pickup 'hum' if not wired the best
and 'super strats' strat style guitars with humbucking pickups tend to have similar tonal ranges to a les paul, but with more hollowness in the middle.
BC rich, Ibanez, Kramer, ESP, Schecter all make very good guitars which would be suitable for metal playing, it's a case of try before you buy! hope this helps
guns dont kill people, people kill people, and monkeys do too (if they've got a gun)