Quick Answers, Project Planning

[YoungDreamer]

Hey, This is my second thread, since the last one i have done lots of research but still need some help and i have a bunch of questions.

Im looking to Build a 65 C-10 or C-20 Long Stepside Pickup.

What would be the best chassis swap? Anything 80's to 90's i could probably save from a Junk Yard might be preferred.

Is a Cummins 4BT the best diesel swap choice for these trucks? on the new chassis and with the 4BT could i go 100MPH?

Saw a guy with a dual cab custom truck, looked like he had leather seats from like an 06 Chevy 1500 in the truck, anybody else see or do this?

If i do buy a chassis with powersteering and power brakes, do i use the existing Master Cylinder or do i need to buy a different one to fit the engine bay?

Im 17 and dont know a ton about old trucks or cars in general all help is good help. I dont even own the 65 im just looking at my options for a fun project that i could complete in a Year! Under $9,000 hopefully!