Thats a good route to go. Try to find some local shop what can do the job for you 100% custom. you can really save cash this way.

I took mind to a place called exhaust pro's, they cut my pipes off after the cats and right before where they go over the rear axle and welded in custom built X-pipe, then they cut off my current tips and put on 3.5in x 18in chrome exhaust tips.

No mufflers in this setup, sounds fantastic with the 3in xpipe even though it is 2 1/4 piping on either end. great throaty growl that hits a nice monsterous roar when revved high. When leaving the parking garage at work i can set off alarms if i rev the engine nice and good. <g> At idle it has a nice bassy buddabuddabuddabudda. Definatly sounds like a monster. You can probably squeeze a tiny bit of HP out with some type of mufflers, but i figured i would up the power in other areas. I wanted the straightpipe sound and i love it. That was my first mod to my car and 2 months later i got about another 1,000 worth of work done. This is addictive.

Total cost of this was 250.00 and it took em 45 minuits to do. Quality work, and you dont have to pay extra for a name brand. after all, it is just pipe work. No reason to spend a lot of cash on something that simple. I say stay away from the brand name shops like meineke and midas and go for a place that specializes in exhaust and performance exhaust. Some of these places see a lot of mustangs come and go and have templates for making H pipes and X pipes and will make extras when they dont have much work going on, which saves you cash and you get something made by an experienced welder, not some machine

I had to take my car into the dealer recently for a leaky main oil seal, the head mechanic called all the other mechanics over and showed them the welding job that Exhaust Pro's did and told em that is how a weld should be done. <lol> So apparently they did good work. However, to fix the rear main seal they had to pull out the tranny, and to get the tranny out they had to remove a portion of exhaust that no longer unbolts. My entire exhaust pipework has been welded to be 1 solid piece. So i had to pay $160 for them to cut off a portion, remove the tranny, fix the leak, replace the tranny, then weld it back on.

So keep that in mind if you are worried about warranty issues. I had to pay them to cut out the exhaust but the rest of the work was free.