ATV down hill bike

Hi to all PB fams and users, I have decided to attempt and build, a Fully functional 4 Wheel DownHill bike, Some think its dumb, but if it works it works, if not well i had a good shot at it.Over my years of using pinkbike as a information center, as well to see what has occured in the biking community that's different and new. I have yet to see a fully functional 4 wheel down hill bike, aside from the ones used, by handicap people. I would like to see i i could rig up a ATV chassi, with bike tires, and a chain drive. For this I'm looking at for parts:

1 Some Bmx or all mountain cranks, as well BB.

2 A 2 chain rings to mount to the cranks.

3 Some extra chains,

4 Rims (walmart bike style) what i mean by that is one inch wide by half a inch this, i would like two 24 inch rims, and two 20 inch.

5 i need one 8 speed derailleur, with triggers.

6 and finally two 20 inch dirt tires, that's are 2 inches wide, and two 24 inch that are 2.35 to 2.5 inches wide.



If there is any one that could help me out, by giving me special prices that would be greatly appreciated. thank you and enjoy the ride.