I plan on buying a MIG welder in early spring.
Two things I want to have are:
1)The ability to weld Aluminum
2)120/240v option

I am looking at the I-MIG200 and see that it has a built in spool gun capability for Aluminum. I see that the SM200-N spool gun would be a perfect match. It also says "Miller compatible spool gun", does this mean it will work with Miller welders?
Will Miller spool guns work with the I-MIG 200?

Also in the description for the I-MIG200 it said....
"Equipped with a unique Stick weld function, the Power I MIG can also double for a scratch start TIG power supply"
I have no clue what this means? I can use the I-MIG as a TIG welder?

Another thing I'm wondering is what is the maximum thickness material you can weld with the I-MIG200 plugged into 120v?

I'm just trying to narrow down what I need/want so any help is appreciated.