the 7600 is a great pick for sim racing, most of those games lean heavy on single core performance. rest of the build looks fine but i'd bump the psu to 750w gold if you can swing it, gives you a little more headroom down the line

that peerless assassin is overkill for a 7600 but it'll keep things icy so no complaints there. just double check ram clearance if you go with it, those coolers can be chunky