PERC = Polaris Electronic Reverse Control. I have not seen or heard of any companies making after-market. Skidoo and Polaris had it stock for years, AC finally got on the bandwagon this year. Skidoo came out first with the patent. You would need the ECU, a flywheel with the correct timing, a secondary that will work in reverse, an oil pump that will work in reverse, a recoil that won't self-destruct if the rope is pulled (even a little) while the sled is in reverse, and a button to engage the system. Polaris started their PERC about 03 and you can retro some of the pre-03 sleds with the items I mentioned. I don't see how you would fit it onto a Cat.
There may be other companies offering some version of electronic reverse, I have not seen any...