Questions on MIG Welders

[Jay H 237]

I've posted this here since a lot of teams weld and they might have some suggestions or insight for me.

I'm planning on buying a MIG welder within the next few months. I'm deciding between this one or this one. I'm leaning towards the 140 (the second link) and I know where I can get it cheaper than listed on the Hobart site.
This will be for home use mainly and I may use it occasionally for my team. I'm planning on doing some work on my car this winter and need a welder. I want a 110v model since I don't have 230v in my garage (I could add a 230v line if needed though) but with the 110v models capable of welding up to 3/16" to 1/4" that's more than what I think I would ever need especially for body work. I know the 110v models have a lower duty cycle but that doesn't bother me. I've never MIG welded before. I've got experience with acetelene and arc welding only. I'm getting a MIG for the fact that it seems the most universal of welders and the fact that doing body work with an acetelene torch is asking for major heat distortion. Working on a car is my main objective with this welder. I have some spare body panels I'm going to practice on first.
What I want to know is if anyone has any experience with any of these two models or any others (Hobart or not) I might want to consider. I don't mind spending up to $500 for a welder, I just don't want a piece of crap or something that won't meet my needs. I'm planning on keeping this welder for the long term, not getting rid of it once I'm done with it. Another question I have is these welders can weld with or without gas shielding and when I set this welder up which way should I go? What are the benefits and downsides between gas and gasless? What shade helmet do you recommend when using one of these?
If you have any suggestions or anything else I might have overlooked/or not realized, or any tips when using these let me know.


P.S. In case you're wondering I'm going to drain and pull the gas tank from the car and disconnect the battery before welding. I just have a feeling someone would ask that question sooner or later.