I would check with the fire house, and see what they can fill. Some Scott packs use 2260psi wile others use 4500psi and most scuba tanks take 3000psi. So get a 12 pack and take a ride down to the fire house and talk with them first . Find out if they are even willing to fill first off, then what they can fill ,they will steer you in the right direction and might even have a tank for sale or rent. Or you can do what I just did . I just rejoined the local fire house and as a perk I get FREE fills HeHe