I'm new to Steel Challenge and putting a pistol together for RFPO.  I have a VQ Mamba coming that I will be putting on a MK iv 22/45 lite frame.  I want to put a Cmore railway sight on it but there are several options.  My thought is going with the polymere model with the click switch and 8 minute dot.  Would this be the correct option for my set-up?  Where is the best place to buy these sights?

I've not shot a lot of steel challenge but I'd personally go with a larger dot, like an 8min or maybe even a 12min dot. I shoot an 8min on an USPSA open gun and at 35yrd that completely covers the "A" zone.