[grannyknot]

A mig welder is a wonderful tool to have in the shop, and as you alluded to, all sorts of welding jobs will pop up once you get proficient.
I would advise not to buy that elcheapo HF welder, only an experienced welder could get a decent weld out of those machines, they are very limited and frustrating.
Have a look on Craigs for a used entry level Lincoln welder, you won't regret it and if welding isn't for you, you will get every cent back when you sell it.

Using fluxcore wire means you don't have to invest in gas tanks but be prepared for messy welds with lots of splatter.
Mig is probably the easiest to learn on, it's very forgiving and your welds will improve quickly.