Performance exhaust

[TurboSDL]

my exhaust looks like crap.. i need somthing new. i was wondering if i put on a 3 inch pipe from the downpipe back if i would gain any power? or at least not loose any power. or better yet the turbo back, maybe a reducer from the turbo to a 3 inch from the turbo back, and then to a flowmaster diesel muffler or whatever anyone could recomend for a good muffler. I have no muffler or resonator right now just the stock exhaust with that stuff off, it is starting to sag and whoever i bought it from has a downpipe on there that hangs down way too far causing the whole exhaust to be too low. i dont want to loose any power i have from the straight pipe but i would like a performance muffler if i would not suffer any power loss. otherwise id like to do 3 inch all the way back.