Check/refurb/maintain all stock systems. Fuel/brakes/suspension/steering/cooling/driveline/ignition/tires/etc. Hoses, lines, belts, bushings, etc, etc. Get everything sorted. The car will make the drive without issues if everything is working correctly. This will take most of your budget. Swap on a dual master cylinder like Dave says. I did one on my 65 C10, still on the stock master on my 65 Impala.
Two doors, four doors, wagons, and ragtops.