When I was out in Seattle, I packed mine up and sent it to Tony at astroperformance.com as they are of the best Mustang transmission shops in the country.
dont know how far you plan on driving but i had mine rebuilt by Mike at OC Gear in Garden Grove.I also sent a few people there and NOBODY has had any issues.
Orange County Gear
12862 Joy St
Garden Grove, CA 92840-6322 map
call pro gear in kearny mesa and ask if they have any good recommendations. they put together my 9 inch rear and through their recommendation another shop narrowed my housing. i know this is not a trans recommendation, but i am sure they (pro gear) will not steer you wrong.
I'll do it for $350 out the door if no hard parts are broken. If stuff like 2nd gear needs to be replaced, that's slightly extra. I'm in corona. I'm not a business, but I have a LOT local's who've gone through me, including a couple from the sd board socalstangs. v8onlY@yahoo.com