I'd say go with the lincoln one from Home depot posted above. Its a 120v, has a gas regulator, its pretty versitile, and will bodydrop your truck just fine. I know some cover trucks built with old flux core welders.
that looks like a good little welder for the money. takes up to a 35 wire, which is pretty good sized for the frame parts. just crank it all the way up and have the edges chamfered (beveled) to enhance penetration on buttwelds (like frame z's).