Jpipe/exhaust owners (Test Pipe, High Flow cat or stock cat?)

Hey as some of you know, I am getting ready to pull the trigger on the ATLP resonated cat back exhaust system as well as ATLP Jpipe. For you guys running an aftermarket J pipe and exhaust. Are you guys running your set up with stock catalytic converter or did you switch out to test pipe or high flow cat? If need be I might as well just buy everything all together. I will also be picking up my CT Ice box as well.

Thanks for the input!