I put on a Cherry Bomb Stainless Steel Exhaust Tip. It is a clamp-on and it has a 45 angle cut. I can't remember the size but it cost around $20.
This my be it but check the size first. http://www.summitracing.com/parts/imm-577457/overview/
I got the 12" one. 18" is to long. I did not cut the factory pipe.