I'm in the 'anti-EMG' camp. I just think they take all the personality out of the guitar, and to an extent the player. The tone they produce seems artiicial from the off to me.

DiMarzio pickups are the best for me. The Evolution is great I think for high gain, and the PAF pro is amazing as well. If you're playing thrash you're using a heavy distortion anyway? I'd go passive so that you have the option to play other styles as well. Do yourself a favour and go find your amp and effects pedal(s) in a store, Get the kid to hook 'em up and plug a Jem or JS in... :)