With a tig, things are different. The fact is you NEED big for aluminum, and you CAN BUY big because of these dinosaur transformer machines that are out there. A 120V AC powered welder is going to go nowhere with aluminum. Yeh. There are lots of import/ DC only tigs (inverters), and you can't weld aluminum with 'em.
The fact is, you can "rig" an AC buzzbox with a high freq converter and a bottle and "do aluminum." But that does not get you a foot control, and with guys like me who are struggling anyhow, not having a foot control is a killer.