small hpa / disco conversion

[air commando]

I am building a gun starting with a disco tube I would like to fit a small HPA tank ( 8-10 cubic inches ) at the gauge port ,to get more shots per charge . Are HPA tanks available this small ?
My idea is to use only the tank no reg. . By doing it this way , I would be charging both the gun and the tank . I need a source for the tank ,as well as a source for high pressure fittings ? Any and all help will be greatly appreciated . Max fill 2000 psi. Comments & suggestions welcome .

Thanks ,
BOB

[Kailua]

Wouldn't a Disco double tube work for you?
http://www.stalwartarms.com/disco-double.html