[knutso]

I would go with the univega , the GT looks too big , the mongoose might be fun to smash around but would most likely have issues with the fork and components just down the road.

Check the frame/fork for excessive rust, cracks, check the teeth on the chainrings and cassette , make sure the brake/shift levers are tight and functional .. make sure the wheels spin true .. and go for it Univega FTW