I saw in your other post that your car already heats up in traffic, humm.
You can go with original but there are lots of pieces to find. Each one of these cars have a unique wire harness built for what came on the car.
On the over heating. I have a 73 vert with 351 C. The PO had bored the engine .050" over cam, put Edelbrock performer 2-V to 4-V intake on and MSD. It also has AC, PS and automatic with shift kit and higher stall converter.
When I got the car he had not driven for 25 years and I figured out he had installed a head gasket backwards. It would almost get hot and would blow coolant out when you turned it off.
With head gaskets right, correct baffle in the block and correct 292 deg. cleveland thermostat I have no issues. I did also install a stand along fan cooled transmission cooler.
I drove to Charlotte couple weeks ago in 90 deg. + heat and drive around town here an in mountains. So it has stock radiator so you can make them run cool with AC. It is stock system but it did develop a leak I need to find.
I also run 90 octane non ethanol fuel with the Lucas gas additive in it.
You could probably buy a rusty parts car cheaper than you can buy system for. New dryer and rebuild the compressor, etc.
If not trying to keep original just hang aftermarket on.