What gauge wire do i need?

I'm getting ready to put in a 220 circuit for a welder. The manual says 220 voltage +/- 10% 50/60Hz, as i understand it standard north American power, input current shows 1 Max=29A, 1 leff = 22.4A.

Now i'm assuming that's per phase, because the manual says "Input Single Phase Only" and i need either a 50 or 60 amp breaker double pole breaker.

Do i need a 50 or 60 amp breaker, I'm leaning towards 50 amp so the breaker will trip before it reaches its max, which if i'm reading the manual right is 58 amps, and what gauge wire do i need? The plug is going to be about 15, 20 foot from the panel.