hey guys, i looked in the search menu, but am getting confusing information.

If i want to run a wire a from my panel to the front of the garage (about 25 ft), would i use a 30 AMP breaker with 10/3 for the wire, or would i use a 40 amp breaker with a 8/3? Also, would these need to be single pole or double pole breakers.

Finally if i wanted to run a wire out to our shop from the panel, about 75 ft, which type of wire, and breaker would be necessary. Thanks .

Finally again, for welding 2x3" 1/4" steel, would i use a 100% co2, or the argon/co2 mix. Is the stock regulator/flowmeter not set up to use pure co2 shielding gas? It says in the manual to obtain additional parts.

Sorry for the long post, its kinda my first real welder and i'm just learning.