Good thing for magnets, right Bob?
Totally agree with going with the 16g. Nothing wrong with a combo. Just means 1 less "nailer". But, as stated above, the "nails" are the real cost.
Just a small note about air nailers, if you take good care of them, they'll last for a long time. Some good ol' fashioned regular maintence and they'll last for a long time.
Ken