FWIW, I just went through many of the same thoughts that you're having and after doing some research and reading a lot of information on welding/fabrication boards, I decided to go with a MIG unit and do the stand myself. Stick/arc units are cheaper, but everything I read (and have now experienced) talked about how easy it is to learn how to do a passable job for this type of stuff with a MIG unit. If you end up with a MIG unit, try to find one that handles gas as well as just flux-core welding. It'll be much more flexible that way in the future.
While I welded up my stand, I would agree with what the others here are saying about weldless keggle fittings (or having someone with sanitary TIG skills do it for you). From what I understand, neither a MIG or stick unit is well suited for doing the sorts of things homebrewers like to do with keggle fittings.
Anyway, here are a few pics of my new stand. It wasn't the cheapest route to go, but it will give you a new toy and a skill that will probably serve you well in the future. Plus, if it's anything like my experience, it will be a lot of fun
