Mini/micro co2 system

Ok I'm looking to make some slight upgrades to my small box (1.5ftx2fx3ft)
I'm think roughly along the lines of something like this http://www.fosterandsmithaquatics.com/product/prod_display.cfm?pcatid=22518&cmpid=03csegb&ref=3312&subref=AA&CAWELAID=733997492

My only thing is this is the only one I could find? Any suggestions would be great. I would live to find a system the allows use of refillable paintball tanks or the little disposable cartridges that you can use for paintball guns and are easy to find in any walmart or similar store so I don't have to constantly be ordering from a website.

Really no one has ever had this idea? Someone has to have some thoughts

Never heard of something that small for CO2.
If I was going to do that, I'd just get a full size tank and regulator...
Have you seen the CO2 bags they sell? http://www.afgrowsupply.com/exhale-co2-cultivator-natural-co2-generator/
This could be a solution

Yeah man, im interested in getting something like this goin on too. I even thought of whacking some sugar water and yeast under in the corner of my tiny cab, as the fermentation gives off Co2.. then i realised i was totally blitzed..