The only thing I'd say there, is with aluminium you need a lot of current.

And there's even times when my 200A machine is pretty much at its limit say doing an intercooler or something, as the heat can soak away so fast.

So l'd say a 200A would be the minimum to consider.

Although 170A will certainly weld. Mine's an older one with rotary knobs, and it's pretty easy to use. The thought of lots of buttons and digital displays sound more complicated, although presumably they're not ?