Since you are asking I would make the assumption you are fairly new to the action type competition games and testing the waters. So I imagine you need to keep costs reasonable, as well. I would suggest a Mk III or IV simply because of the location of the mag release. Get the mags, practice, determine the most reliable ammunition, shoot the matches and have fun.
If you don't use iron sights well get the Ruger mount and a TRS 25 Red Dot. Typical course of fire is 5 strings of 5 targets. Hence the 5 mags plus a spare. If you find yourself liking it, get a Volquartzen hammer, sear, bushing and trigger. Prove safe and enjoy a nice trigger. Other format stocks may provide improved hold on the pistol so you may experiment there at any time.
I used something similar to this years back but now I use a 1911 22 Conversion on a dedicated frame.