67 C10 4/6 drop recomendations

[shoveldug]

Hello I recently acquired 4 yes 4 1967 C10s They are all in various states. The end goal is to build 1 short bed. It will have a 283 with a 3 in the tree. I am in the process of setting up the frame and drive train as the 1st order of business. One of the frames was originally a Oklahoma truck. This is the one I am using. I have already cut this frame from lwb to swb. Now I want to set up suspension components. I intend to run 8x15 and 10x15 steel wheels. Also converting to power discs in front. Truck will be driven frequently and haul a motorcycle in the bed (1959 Harley Duo Glide ) and pull a small enclosed trailer. I attend many AMCA (Antique Motorcycle Club of America) events. My questions are. 1) should I convert to 5 bolt when swapping to discs in the front and drill rear axles or change rear end. In other words advantages disadvantages 5 vs 6 bolt. 2) In order for the 4 / 6 drop I am thinking drop spindles and springs in the front. For the rear I am uncertain. Due to towing and loading. Drop springs with a c notch? Air shocks for when loaded? Air bags with Schrader valves in the rear for when loaded. A complete air bag suspension is out of the question for me. Thoughts? I want to do this right but also on a budget. I do not mind going to the local salvage yards to gather parts.