I think you might as well order the real Rob Allen bands and shafts from
http://www.flfreedivers.com/
You didn't say whether you were diving from shore or from a boat, but its pretty hard to carry spare anything if you dive from the beach.
On my boat, I have spare shafts, mono, crimps, slip tips, and just about everything else I can think of. I don't have spare bands because they never break without plenty of warning, and I replace them long before they have a chance of breaking.
