Where are you at in GA? It's really not too tough of a job, even for someone who's not too mechanically inclined. All you'll need are some basic hand tools... But, if you don't feel confident doing it, there's certainly enough places around that will do it for you. Mustang Services (
http://www.mustangpartsnservices.com ) does really good work and can also acquire the parts for you.
As far as a good crossover pipe is concerned I've always been quite partial to the Bassani X-pipes. I've had one for going on 5 years now, and it still looks exactly the same as when I put it on the car (besides the fact that I had two hi-flo C&L cats added to it -- I just got tired of swapping the stocker for the off-road once they made emissions testing a yearly event). Sure, you might pay a bit more money for it, but as far as I've seen the quality of the Bassani piece really stands out.
If you're stuck wanting an H-pipe for sure, then it's really either MAC or
BBK. I've never actually dealt with a BBK crossover, but based on the quality of their headers I'm sure it's not a bad part. The MAC stuff on the other hand seemingly always leaves me with something to be desired.