First time 318 or 360 build

Lets say we have a late seventies 318 and a late seventies 360.
Which would be a cheaper rebuild as far as parts go, given they both have stock bores? Would a 360 cost more to balance, as I heard you need a 360 torque converter too.

Is a .020 over bore, etc more desirable? I dont mind spending the money on a rebore.

Ive got a 318 currently in the car, but would like to build up another engine as a learning tool, nothing crazy horsepower wise, just something solid that doesn't smoke or burn too much oil.