Just curious, is space an issue? Any preference between a 5lb tank w/ full size regulator vs. paintball tank w/ mini regulator?
I hear 15 gallon tank and assume smaller stand and preference to keep things hidden, but don't want to assume...
But, If that's the case...
Something like a Tippmann 24oz tank with a mini reg:
good= Aquatek mini off ebay, $80 range last time I checked
better= NilocG mini regulator $100(same guy that makes Thrive) off his site NilocG.com
best= a custom built 2 stage mini(they occasionally pop up in For Sale) $200+
Disclaimer: just MY opinion on the good, better, best
92% of all statistics are made up on the spot.