That's a nice machine tigmaster, but probably way more than he needs. A simple wire feed or Mig welder will do the trick, and will probably be much easier for a beginner to use.
I've used a 120v wire feed welder like this one
to build numerous projects, including a utility trailer.
The basic wire feed welder uses flux core welding wire (no mig gas). The drawback is that you'll have welding spatter and slag to clean up. Most of these can be converted to mig, but once you do, the thickness of metal you can weld goes down. The MIG gas virtually eliminates spatter and slag.
If you can do 240v, I'd recommend this one
. It comes with a gun for aluminum, which is an extra on most other's models. With a different gas mixture and stainless wire, you should also be able to weld stainless materials using a mig welder
If you've got a place to plug in a 240v model, I would go with that, because you'll be able to weld a bit thicker material. But if not, a 120v model will do for what you've described.
I'm not a professional welder, but this has worked great for me.