You definitely want the gas. As far as recommending a welder, what's your budget? You definitely want to stick with a brand name here, Miller, Lincoln, Hobart etc.
Miller - Has an auto-set feature for to help people set up their welders but is more costly
Lincoln - Can even be found in home depot, no auto set feature
Hobart - Essentially the same unit as the miller but lower price, and I don't believe it has auto set