Jay, I myself use a SCBA setup, but that's because I'm in the fire service and have access to unlimited air here at the station. If you can find someone that will fill to 4500 psi (ie. paintball shop) then I'd go the SCBA 4.5 route. The only down side to SCBA is the carbon fiber bottles have a 15 year shelf life. I don't know much about SCUBA setups but I believe there's three options, two of which you wouldn't want due to the lower fill pressures. The high fill pressure option (I think it's a max of 3500 psi) is only available on a steel tank (which gets heavy) but sizes range from about 15 cuft to over a 100. I think most guys using a SCUBA setup opt for a HP 80 cuft tank which uses a DIN valve. I'd recommend going here for all adapters and fill hoses:
http://airtanksforsale.com/, exceptional quality. Sorry you had to find out about the paintall cylinder the hard way. Cheers. Steve