ya bar stoold would be better for weight but if you talking about six of them its going to get prety expensive but if u get 2 junk couches its free and besides you wont get much sped out of it either way because of the weight of all the people will force you to use a very low gear ratio even with a torque converter/2 speen jackshaft
I think the barstool idea is cool. I'm finding that the weight adds up real fast when making a multi-person vehicle. So it probably won't be for racing around.
you might have people falling off of them easier than you would a sit-down bench seat, but it would be killer awesome. and you could add a bar to the vehicle so they'd really be bar stools!
i thought you couldn't drive around inside burning man?