Originally Posted by
Piff
I think a 90s hybrid with horizontal dropouts (I'm just guessing there are some out there...maybe not?) or an old MTB/ATB bike with horizontal dropouts would work fine. Just make sure to avoid the mountain bikes with u-brakes on the chainstay, usually models from 1986-1988. If he's that strong and heavy he might be better off with the smaller and stronger 26" wheels.
Why avoid the u-brake? They are a little more work, but if they come across a deal I don't think it should be a deal breaker. He might even be only running a front brake.