Exhaust for toyota truck

i have single cab toyota 4x4 p/u with a 22RE, and im lookin for a pre-fabricated exhaust cat back system. what all brands are out there, what kind of sound do the exhaust systems produce, what kind of power gains will i get, and what is everyones opinion of the overall best value? if yall have answers to ANY of these questions, dont hesitate to post. im gettin sick of stock exhaust!!! thanks a bunch

trent