I've used a few different SC harnesses, so far the best one I have used is a good old shotgun belt. Pockets work good for me for a dump pouch but the wife does perfer a Crown Royal bag hanging off her belt as a drop pouch.
CCI is a good place to get springs. Or you could talk to Rodney (RTR) and pick up theinsert to use Autococker springs suck as the Madmann kits which are easy to find and inexpensive.
Good luck and I hope you love the gun.