I just freshened up a go-kart with my girlfriend, so she could ride too. Just need to make a few small changes and order another part or so and it should be perfect! If you take a look through the old threads and find the "Go-Kart" thread (probably the only one on here), you can take a look at it. Not sure what kind it is, but it's decent.
I can't wait to start working on my columbia again and hopefully have a few things to ride by spring time.