Get the A/C ,D/C one most of the time you'll use D/C as most rods run better on it. Some rods run on both. You will be limiting yourself and have to buy again just to save a little in the beginning. David

anccrick,
I fully agree with David in that AC/DC machines are far superior to an AC only machine, but I believe that you may be better off to simply stick to an AC machine. I have built and repaired many, many things in our farm shop with my father's little red Lincoln "Crackerbox," all of which I was able to do without a problem. This includes repairing 3/8" thick 4"x6" square tubing on an offset disc's hitch, which I then reinforced with scrap 1" thick material. Said welder has been in use on our farm probably as long or longer than I have been walking on this earth, and I cannot remember one time when repairs to it were required, nor once when the duty cycle was exceeded.

The machine will run 6011 (THE most common rod you will ever find on a farm), 6013, and 7018 with ease, and I believe that, for the money, it would be your best choice for what you plan to do.

Hope that helps,
G. L.