Well you want TIG for sure and of course you will also have a fine stick welder to boot, in the same machine. Aluminum calls for a AC and DC machine, the other question is how heavy aluminum, because as it gets thicker the size of the machine and cost goes up. I'm partial to Miller products and I owned a SD-180 with the foot petal control at one time. Never used enough to justify, ended up now with a DC only lunch box size invertor (14lbs) from Miller. Does TIG and stick, but no AC. I love it, cause I can take it anywhere, 120 or 240 volt, autoswitch over, just plug it in and go.
Retired - Journeyman Refrigeration Pipefitter - Master Electrician - MakerGear M2 3D printer- ULS Laser Engraver