Yep Kenmac reg works a treat, but you are wise to restrict the usable pressure to 12 bar. I found that the extra power at 16 bar simply used up CO2 faster, and didnt add that much to the flip... except shearing the ram mounts.
Using the flipper calculator that Noel developed on the Hassocks Hog site, I worked out that 14 bar gave the best mix of power and number of flips.