At your level you dont need a DP yet.
I have a Postons 3" pipe, which is about the same as the Kirban one. It doesnt fit that great, leaks a little, and looks like crap compared to a THDP. But its $300 cheaper
Some day I will get a THDP, but not for a while. I only changed because my stocker was done for
Put your money into a scan tool if you dont have one (not in the sig) or maybe alcohol injection. Even a Hooker catback would help out more right now.
I'm using that pipe. It fits but I had to weld it to cat to ensure no leaks. If you buy only the pipe from Kirban, the end toward the cat will be straight. Therefore, you have to expand either the cat or pipe end to connect them. If you buy both from Kirban, he advertises that he will make that fix.