there is no weldable metal on a standard vehicle over 10 gauge
110v machines are fully capable of welding 10 gauge in a single pass
i welded my whole truck frame and lots of the sheetmetal with a 110v fluxcore machine
i bought 110v for portability, i've had it on ladders and in a basket on a forklift
you can't beat fluxcore for welding outside.
i've had my lincoln weldpac 100 for 14 yrs and have never had to run out to fill an argon tank
that said... a 220v mig will be more versatile for more metals and methods
most welders have 4 to 6 heat selections and infinite wire speed
i prefer lincoln, miller and hobart, in no particular order.
but lately have heard a lot of good reviews on the eastwood brand welders
stick works well if you have an arc welder available, but i would not buy one unless you have a specific purpose, same goes for tig
welding is all about heat, puddle control and penetration.
once you master those all welding is pretty much the same