Go for it! I will say it would look cool, functionality be damned. You originally asked how much air a titan tank holds. In case you still need that number, it's around 350ml.
Thanks a lot again guys (and gals?) for all the info.
It seems that I will stick with pumping. Now to move onto my next crazy idea that probably won't work out:
Maverick's revolver components into a Longstrike; purely for aesthetics mind you.