The reasons you got yelled at in the COB forum were:
a) They're a bunch of assholes in there (and it's only getting worse)
b) Thousands of COB fanboys ask that question every day because they think that just by buying a certain combination of amps/guitars/whatever they can be just like Laiho.
So, with that in mind:
He's been known to use Lee Jackson pre-amps, ENGL power amps and Peavey 5150.
But of course his sound comes mostly from how he plays (which is true of every guitarist). And for fuck's sake don't turn into another COB fanboy. There's enough of those... I'm not trying to be mean, but it's gotten so bad I can't even go into the COB forum anymore and I'm afraid to tell anyone I actually like the band.