The 2250 (non XT) is really an easier platform to get power out of and parts for. You might want to check out a neat adapter that a member here is working on (to sell soon) that will allow you to put a CO2 or HPA tank on the back of a regular 2250 with out having to buy any 2250XT parts. You would then just use the kit from B&A (or others) like the bulk valve, tube end cap for bulking, etc. The other neat thing about this adapter is that it will allow you to break the gun down into a backpack for transport.
See the photos of what he is working on at:
(scroll down at the link above to see photos)
Note that you can have a pressure gauge, and possibly a burst disk (good for using an HPA tank)