first off what are you going to primarily use it for?
if your looking for a decent all around setup to do body work and light (ie 5/16 - 3/8 or less) fabrication and Hobart handler mig or something similar in 110v or 220v would do ya fine. the 110v is alot more portable of course. but the 220v will let you weld thicker steel (higher amps) and less of a duty cycle.
now if you are just wanting to learn to weld and are not planning to do bodywork or sheet metal i would say a Lincoln buzzbox stick in 220v would do ya alright. i have built ALOT of stuff with my forney arc welder that is older than i am
dont ever get a 110v arc welder..they are a little more than a over-sized battery charger.
another option is a fluxcore welder. almost any MIG can run fluxcore but most fluxcore cant be converted to MIG. flux core is OK for most stuff but it runs hot so it makes bodywork a nightmare.
TIG you can use for anything steel, stainless, and aluminum. it is a very clean process in that you do not have any slag to clean up and you have so much better control over the weld. so much that you can weld a piece of like 22ga sheet to a 3/4 plate and have good penetration on both pieces.
the draw back is it is PAINFULLY slow and is not all that great for out of position welding.