Well, right now i have my pacesetter header to stock piping, to a glasspak, to 2.5" piping to a Tenzo R muffler with a 3.5" outlet.

What im thinking of getting is 2.25" from downpipe to a high flow cat then to a Tsudo N1
Tsudo N1 style

If i change everything, will i get a lil more performance, or should i just get rid of the muffler?

well if i was going to upgrade an exhaust i wouldnt just get another look-alike model like a Tsudo N1, if you are going to upgrade buy the real Apex-i N1. and my other opinion would be, you already have an exhaust system thats freeing up quite a bit of air flow, id spend the money elsewhere, upgrade your engine electrical or fuel systems before redoing the air system.

well, i thought about it, and im gonna keep it the way it is now. Spend my money on my new car.