FORKED WHEEL W/DISC BRAKE

Not sure if this will get me anywhere...but since there's a lot of custom car stuff going on here maybe there's a chance....   I am working on this custom....let's just call it a car for now.    Instead of the traditional axle type suspension,  I want  (need) to have a forked type of pivoting suspension on both sides - ie like a motorcycle.   However,  It's going to weigh 6-7k.   So a traditional motorcycle tire, brake, wheel assembly isn't going to cut it.   I want (need) R15" 10 ply trailer tires.    

So the fork part can be fabricated,   but does anyone know of a source for a wheel/brake assembly out there that could fit into a beefy custom fork like what I'm describing?  Or could a traditional car type wheel assembly perhaps be (safely)  modified to go into up  a fork?     Thanks!