if you need to weld out doors
use straight co2, and an e6 wire
and turn the gas flow rate up,, co2 is fairly cheap
all you need is some form of windbreak to keep down wind at the weld zone
the use of co2 which is heavier and denser than the mixed gases will do a very good job
with a bit more spatter.. i have welded outside without much issue useing little more than a piece of plywood
to shield the drafts.
there is a place for flux cored wires, but in reality i have found that working around the limitations of drafts
and using gas shielding to be well worth the effort.
it isn't often you will need to weld in a hurricane
my point is, get a machine that uses gas,, it can be used without with flux core
but the cheaper flux core machines don't always come capable of adding gas later
and when they are it isn't a cheap upgrade.
on thin sheet metal, there is no way i would even mess with flux core wire
just too much of a pain to prep and chip,, using .023 wire and gas makes sheet metal work
very easy , nice and clean.
bob g