Another vote for the LPA adjustable rear. Put on my 75B for USPSA. At first I was wanting a 3 dot system, but found out that the rear dots (just like the pros here told me) were distracting from fast shooting. For accurate/bullseye shooting I would go three dot.
My front sight for this setup is a standard front sight drilled out to accept a FO rod which you can get for about 5$. Call me cheap, but it works great! 1000s of rounds downrange no probs.