talk to your local shops, your local
stang club, and your friends for a good shop and good local prices. For any duals you are looking around $250 on the cheap side to $425 on the normal side. Most shops don't care whether you want an h-pipe or true duals, but true duals should be cheaper then fabricating an h-pipe. I would go to a shop that has their own pipe bender. If you ask for an x-pipe, then expect them to laugh at you and ask why!!! lol.

It is only a v6...
The hard part, atleast for me, is cutting your bumper, since most shops won't do it! or you can get a gt bumper of course.