110v is a smart option, if you need it somewhere away from home! If not, you have 220v so use it! I do not believe there’s any benefit with duty cycle 110-140 @110v but arc stability might have a difference in the 140-180 amp @ 110v so if you decide 140-180 go 220v and remember you lose the freedom to take it out of the garage in a pinch!
120 - 140 amp ideal, but say 140-180 is best to have on hand later down the road, if you think you could really get into welding, and see a need later on aim for 140-180.
Mig is not must!
Flux core is great for a beginner, once you get decent then run gas if you feel the need.
A person who doesn’t know how to weld can still weld ugly non penetrating spattered welds with gas, I think FC makes you a better beginner, forces you to do proper technique kinda, and even with FC you can weld just as nice as mig with little spatter which can be easily remedied with a soapy water spray and just wipe the weld seam dry with a rag, but the biggest thing with FC is technique the angle,direction,distance and speed all have a effect on how bad the spatter will be.
Spool gun has no use to you yet, or maybe ever so I believe it’s not even a option to consider.
There’s a lot more to welding than most beginners imagine especially if you never been around it, there is preparation and a lot of safety to think about.
Do you have any experience trying it, ever around someone welding?
