Most people only dispense with the paintball tank and they dispense and carb with the 5# tank, so you can probably dispense a lot more than one keg with a 20oz tank.
On tap: BCB Porter, $12 Cream ale, Amarillo Pale Ale, Simcoe Pale Ale
Kegged: Amarillo Pale Ale, Simcoe Pale Ale, $12 Cream ale
Primary: Calypso Pale Ale (x2)
On Deck: Lake Walk Pale Ale, BCB IPA