what is the difference between the tbi sshood and the tpi? and whats the chepest place around to scoop one the hoods up.

There is no difference in the hood itself.

If you are talking about setting up some sort of forced induction, then the airbox would be different, but the hood would be the same.

And in order to scoop up a good, cheap hood, see those boxes at the top of every page? Click on the one that says hawksthirdgenparts.com. That's probably one of the best places to get it. You could try the eBay ones but I haven't heard first-hand experiences with the eBay companies.

Hope that helps.