pimped pistol

i want to pimp out my pistol, but as it is, it runs on 12 grams and the ****ty 10 rds spare on top. its a pirhana usp. i want to upgrade the 12gram, so that i could run the pistol off a tank on remote. Scott said that i could maybe find a 12gram, that has a bottom line or stel macro or whatever the hell screwing into it, but i havnt had much luck in finding anytihn of the like. anyoen have suggestion for that?

the other mod, is that i want to take off the top feed tube, and put something on it like the pump-cocker / phantom feed tube, where i could simply reload with a 10rd pod. i havnt been able to find these feedtubes anywhere on the net, HELP.