so you don't need to buy guitar pro and use powertab. you can use tux guitar it's free and i have with it no problems. guitar pro is more powerful but i just read tabs, not create, so here goes link http://tuxguitar.herac.com.ar/
and tabs search engine from many sites
http://www.911tabs.com/

ps:
one of my favorite sites metaltabs.com have no permission to publish trivium tabs, anybody know why?