Hi, I only carry one small 10KG cylinder of 404a, the other I have either statched at a customers store just of the motorway. (large cylinders) or I collect/get delivered from the wholesalers dependant on how quick I need it. Anyway the systems I work on are of a reasonible size, I usually require 60Kg bottles, not many carry these in their vans.
I think Mikes idea holds water, anyway I wouldn't mind a pick-up either.
Regards. Andy.