That 18x series hobart (probably made by Miller) is a good choice. The 211 has some more bells and whistles, especially the autoset feature which would be nice, but there's a chart inside the wire roll door that gives you the settings for various wire sizes and material thicknesses.

None of these will weld AL worth a damn without at least 220v power and a spool gun like the optional one on the 211 data sheet. I like the 110/220 convertible units with the gas regulator. Gas welds are much neater, less spatter, less ash stuff.

I really like an auto darken helmet. Otherwise, you have to position the torch helmet up, and then flop it down without losing the torch position and trigger the welder on. Easy to miss your start spot. You can buy autodarken inserts for most any helmet. Cheap ones tend to autodarken under the right flourescent lights sometimes, a nuisance.

If you weld, you need a 4" grinder, trust me on this one, with abrasive wheels and flap discs and sanding wheels and a wire cup brush.

I found the Haynes Welding Manual to be very helpful, both with equip selection and how to weld instructions. Quite complete. Buy it before you buy anything else and read it.