Thumbs up on the auto-darkening helmet... I got mind from Harbor Freight for 50$. I think it is pretty good. Then again, I have had no experience with any other.
Regarding the welder, I have a Lincoln weldpak 100. It runs off of 110v, and supposedly does well for up to 1/4" using fluxcore. Since, I only tool around, and really don't do anything major, just exhuast work, frame bracing, sheet metal stuff, etc... It has been pretty good. I also have the MIG conversion for it, which I don't use much. I find that the fluxcore wire is most practical for my use. The only problem I have found with the fluxcore is the need to remove the slag completely when needing water/oil/air tight welds. I'm still learning.
I got it used for 200$, which came with a cart, the mig conversion kit, and a few tidbits. I think I got a really good deal on it.