Driver...that's open to how much driving you plan to do. The more you plan to drive it, the more you need to go thru everything to ensure it's all in good working order.
For example: How old are the fuel, brake lines? When was the last time the gask tank and radiator were flushed or replaced? what kind of condition are the leaf springs and front suspension? Engine? what are you planning on? Keeping it stock, untouched? How many miles? Does it need a re build?
Outer panels? If you're car is from the rust belt, you're likely to have some inner pannel rust. (Rust on the inside of panels) Rust never sleeps. Huge variable on car to car past life history. Without pics, no one but you can make that determination.
Ever try to mig weld rusty floors? Good luck. Burn thru will happen a lot trying to patch or repair.
POR. I heard too many complaints on it. Rust Bullet is worth a consideration.
As far as what you plan to spend: Whatever dollar amount you attempt to calculate...double the figure. That's what I hear and am seeing now myself.
Body work: A 5 footer? A 10 footer? If you're experienced, yeah it's feasible doing it yourself. Some just do one panel at a time. 300 hours my friend has on his old Ford right now he's just finishing on. He did it all himself and has easily 4-5K into it on paint and body work.
Some pics would help.