With any electro gun you really do want a nitro tank. Yes you can run it on co2, but it will have a lot of shootdown because of the tank getting so cold and as with any gun, the consistency will be a lot better. I don't know about freezing on the BD, but I am sure someone here could vouch for whether it freezes or not.
On a side note, a revvy is an absolute MUST on ANY electro. Cleaning the paint out of your gun 1/2 way through a game in no fun at all...
Crush your enemies, see them driven before you, and to hear the lamentation of the women...
STFU AND PLAY!!