Chances are, with all other exhaust components being the same, a midpipe setup with a crossover (X or H) should sound better than one without. If price is no object, get an aftermarket catted midpipe. That should give you the best options for sound and still be emissions-legal.
hey i just did the gears for my stang and did them the cheap and better way. basically keep your eye out for a wrecked fox gt with work done on it. i got the entire 8.8 rear end with brand new us strange 4.10 gears and possy for 300 bucks. just switch over the axels and you have a much more peppy get up and go, not to mention a much better rear end. there are tons of 8.8 out there with gears in them, just keep an eye open for a deal.
I've got Flowmaster 40's with divorced mid pipes. Deep rumble, sounds nice at idle, definitely loud. With my 4.10s, it puts 45mph RIGHT in the spot with the loudest drone. Doesn't bother me one bit, in fact I enjoy it. The 4.10's definitely gives it a lot more get up and go, and an XCal2 only increases this more.
$700 for a gear install? Is that with gears and are they made of gold lol or are you saying gears and t-lok? $350 to $400 with just gears i would think. I installed my own so I am not exactly sure but I am pretty sure thats what my buddy paid for his in his 98 gt