Double tracking should do you fine, although I have a sneaking suspicion that Trivium do staggered quad tracking. This is based only on my picking apart of one track for the benefit of a pupil (Dying In Your Arms, IIRC).

The key is the right tonal selection at the amp and the employment of a decent mic, an SM57, say.

I'm actually using my Boss GT-8 run straight into a mixer, so there is no mic involved, I'm using the SM57 emulation on the GT-8 though. But yeah I've got the tone i want from the the GT-8 so I might try quad tracking it, is this going to create any masking problems or something that's going to make notes unclear? I've double tracked each guitar left and right so for rhythm theres already four guitar tracks that's not too many is it? Thanks heaps for that though.