If your looking for legal IPDA speed, then Heinie Or Ky-Tac (High cut). These are the top two holstered used by the SCC shooters where 1911 single stack pistols are only allowed and speed counts).
As for a belt, Rescomp is the stiffest out and should be your only choice. It's a two-piece belt, so the inner goes into your belt loops, and the outer Velcro’s' onto it to keep you legal (can become a pissing match on some shoots since the outer belt does not go threw the loops, but the outer belt without the inner lining will still fit into your pants loops when needed).
On the mag pouches, it’s just depends what you plan on shooting and want you like. The Rescomps will allow you to go both single, and doublewide, plus will adapt to glock and Beretta mags. But these converted mag pouches are best suited for free drop runs since getting the empty mag back into the pouch is less than ideal on the run. Plus, because of the adjustability, you get into pissing match as your equipment is pushing into the speed rig category. To make life simple, just pick up a few Ky-tac mag pouches when you order the holster and be done with it. This way, when it comes time to shoot SSC, your ready to go.
Note on the Heinie, It’s fast but is leather. This holster will break down due to wear and oils well before the Ky-Tac even starts to show wear.
P.S. Take all my advice with a Grain of salt. I"m a USPSA/IPSC shooter were out of the holster and on target past the second mark puts you out of the hunt. If you want to go low budget, then the Fobus holster/pouches* on a K-mart belt will get you started in IPDA for under $40.
*on the pouches, you need to sacrafice a credit card. Cut the card in two the long way, and insert the pieces threw the inner mag retension point loops to tighten up the holding power.