This has been hashed-out here innumerable times, as one might imagine. It all comes down to what sound YOU are looking for/prefer, what guitar feels right for you, what amp/speaker combo works for recording, for live performance, etc. In other words, the variables are manifold, and tastes differ from player to player.
For myself, I still prefer what I call a "classic" thrash/speed metal guitar tone(think early Metallica, Possessed, Pestilence, Asphyx, Morpheus Descends, etc.) with heavily saturated distortion(Boogie-Rectifier tone/Celestion V30speakers) or similar. EMG active pick-ups do agreat job there, I like GHS "Boomer" strings - guitars are less critical if you ask me, so long as it stays in tune and fist you well.
Oh, and I imagine the 6505 Peavey combo is excellent as all in that line are. They usually possess monstrous gain potential and sound gigantic...just how I prefer it for Death Metal particularly.