Just bought a USP 45 myself. It's awesome, mags are cheap at CDNN $19.99 for 10rds with the Tac Floorplates like the ones you pictured. I got to buy a few more, am contemplating the 12s, they go for $50 each just to get 2 extra rounds. I can buy two 10rds with shipping for what a single 12rd costs. The bedspread is cool background also I might add. I previously owned a USP 40C and a USP 40, the 45 give both a run for their money. An armorer friend just put the match trigger package in for me, so I will have to take it out to shoot. It makes the double and single action pulls smoother and a bit lighter, but not by so much its dangerous.
Welcome to the PRO and congrats on one of the best 45 autos money can buy.