I was in the same boat a few months back and bought the Miller 135, the biggest 110 v they make. It is a MIG/flux core welder. I got a pkg deal with the kart. Bought a bottle with gas. Cheap (not self darkening) helmet and gloves. It all came out to about $850 (Alaska price).

Good Luck!
Buddy

"Keep the shiny side up....."
'50 GMC Suburban
'55 1st Chevy Pickup
http://community.webshots.com/user/buddyinak