newbee question

[Coleman]

I've been reviewing the posts for some time and I've got some generic questions on a future project (yet to buy). For the 60-66 year trucks, do I look for the best body and not worry about the motor and trans combo or what. If I'm looking at building a somewhat modern truck with disk brakes, V8, PS and an auto tranny, do I keep the existing frame or swap out to a newer/later model rolling frame and build new cab mounts to fit the cab and box. I would like to keep as much stock as I can but I'm not sure what parts are available, what swaps and what to stay away from. Sorry for the generic, open ended question but I need somewhere to start.