I bought a MAC off road H pipe from mustangs unlimited and it fitted great.. actually, it went on way easier than i thought it would. I have a little gas escaping on one o the joins (ball ands socket type) so i sealed it up and now its all goo.... the sound is amazing, really roars between 2000 and 4000 rpm, then i dont know if the roar stops or if its happening behind me and i cant hear it... but it sounds awesome...
I did the whole install on a set of wooden ramps i made, they only lift the car 10" at the front but that was enough. THe hardest bit was getting the original h pipe off..
good luck with whatever one you choose..
EDGE