Can't Find Regulator for 16G CO2 Cartridge (800 PSI to 400-200PSI)

I am trying to make a Paintball Gun that works off of 16G CO2 Cartridges(800 PSI). I can’t find a compact regulator that drops 800 PSI down to 400-200 PSI. If anyone knows of such a regulator could you please comment it below?
Also I wanted to try using a Ninja Regulator, but I don’t know if the 4500 PSI or 3000 PSI input pressure would work with 800 PSI.