I pick up std AA's (or 9v pp3's) from costco. Own brand (kirkland) AA's 48 for about 8 quid, running my reloader with the full 6 that's 8 complete sets.
If i were you i would buy a Bone Pack from the states,i can get around 14 cases of paint out of one charge,think it cost £33 delivered its awesome honestly here is the website www.dueydogpaintball.com hope this helps.