Cummins pullin truck
 

So if this isn't the right place to post thia then let me know. I have someone who is willing to le me have their 52 chevy truck that has a stretched frame and duals on rear, an old farm truck, and I am wanting to put a 6bt with a p-pump in the truck along with a Eaton fuller 6 speed tranny. This truck will have a flatbed and fifth wheel hitch. Primarily it will be used for pulling a 24 ft stock trailer that will commonly hold about 12 to 15 thousand pounds of cattle. So here what I am wanting for the truck and if yall have answers then send them my way. Obviously the engine is the 6bt amd I want the tranny from Eaton because one in particular can handle up to 820 torque max and I think if I could put the cummins near 700 that would be all that I need for power and I know the nv trannys have trouble. I am wanting air brakes for reliability and something I can air up tires with and for air suspension if I decide to go that way. Im having trouble finding a compressor though that doesn't mount on the engine because ive heard those you have trouble hitting engine mounts. I am also having trouble finding a a rear axle with duals in the range or 88 inches to outside of duals. Another problem is i don't know what gears I should get to get reasonable torque but also highway speeds of up to 75. I know the granny will help with the ratios it has. Any help would be appreciated. If I have anymore question I'll post on here. Thanks