get borlas (genuine or replica) for the awesome boxer sound and low-mid range torque, and OBX for maximum power that sounds kinda like a honda. There are other brands, but none are really worth it because they all do the same thing and these are the cheapest choices that are of no less quality than anything else.
As for the install, the only annoying part for me was scraping off the old gaskets from the engine itself, as mine got stuck there when I removed the stock headers. Other than that, it's a matter of 8 bolts. Enjoy.