I'm thinking of building a sleeper pneumag using Luke's battery pack manifold and an Emag battery pack. Any advice on the "best" regulator and/or one that will fit inside the battery pack without modification to the battery pack itself? I had an old Shocktech regulator that is too big. I was thinking something like a Palmer pebble but was wondering if there were any comparable ones that did not cost as much. Any advice would be appreciated.