you will want gas
do you know what amperage the big machine will go down to?
i would see how hard it is to run some 023 wire in the big machine and try it
if not put the 023 wire in the little machine and see how much of the gas parts from the big machine you borrow for the little machine
thats if you are on a super tight budget
the best would be to just pony up and get another bottle and regulator etc. for the smaller machine