Check out
http://www.colt380.com
That's the Scott, McDougal & Associates website. They do .380 work almost exclusively and their Pocket Carry Package (about $300) fixes just about everything that needs fixing on a Mustang. They do really nice work.
For a photo of one of their full custom jobs, check out my For Sale ad in the Sale/Trade section. I've got a PocketLite with every bell and whistle you can possibly have on a Mustang. It's a sweetie. Selling it to pay for a couple of new toys, but I can't say enough good about SM&A's work.
As for ammo, the Federal 90gr Personal Defense load is about as good as it gets in .380. I'd avoid the CorBon like the plague. Way too variable for my tastes.
The Galco pocket holster and the Milt Sparks pocket holster for the Mustang are great ways to carry the Mustang. I've carried mine in the Galco for the last couple of years. Pretty comforatble. If you're looking for an ankle holster, Alessi makes the best around.
Chad