Stick machines and sheet metal do not mix. Yes, on material 1/8" and heavier a stick machine is great, but you will need a good wire feed for gauge material. Don't skimp on the size if you actually plan to use it often, buy the biggest unit you can since you then have more flexibility. You can 'turn down' a big machine to do small work, but you can't 'turn up' a small unit...
My Millermatic 250 may be overkill to some folks, but I have never had a job too big or too small. I also have had a 220v stick machine for over 40 years and a 110v flux core that is handy for certain jobs, but the Miller sees most of the work.
Now, if we're talking outside, in the wind, then the stick machine is king.
My $0.02