Too vague. What thickness will be most common?
I echo what Tractor Seabee said. Small MIGs are fine for sheet metal, but not for thicker or rusted (clean it off as much as practical) metal. "Pretty" you can get with a grinder. "Strong" is more useful.
There is massive info available on welding forums like weldingweb, millerwelds, hobart forums, etc.
120 volt MIGs are feeble and there is too much temptation to exceed their limits. Terrific for auto body shops though.
Used stick machines are cheap and last for decades. There is good reason farms have so many of them.
thats why i also have a Miller thunderbolt ac/dc welder....220 volt... for the thicker stuff.
Good machine, as is its relative the Hobart Stickmate. Infinite adjustment makes for precise settings, and DC makes for greater electrode choice.
I have more welding machines than I need, but still keep my AC-125/DC-225 Lincoln handy. I've used it for more than twenty years and it's paid for itself many times.
Stick is NOT terribly hard to learn. All welding takes practice, so don't be intimidated.
With stick you can work outdoors in poor conditions, extend your leads wherever you like, and reach places MIG guns cannot go.