Here's a few places and product lines as a starting point. Good luck!

EMP has lots and lots of bags and medical gear:
http://www.buyemp.com/

Gear 911 Specialties has some neat bags:
http://www.gear911.com/

Spec-Ops Brand makes some good stuff:
http://www.specopsbrand.com/main.html

And so does Maxpedition as far as pouches:
http://maxpedition.com/menu.htm

Then there's always Gall's (and old Dynamed):
http://www.galls.com/