What a choice to be made! Mostly it comes down to personal preferences -- on the one hand -- on the other hand. If both are in similar good shape you can be looking at 250-300k more miles with minimal expense with either car. 2 doors looks nicer but they are heavier to open. 4 doors kind of clunky looking but I like to be able to lower the rear windows a few inches to keep the draft off the front seat occupants with the front windows down. You didn't mention which transmission your car has--or the other 242. I like the M46 and have that in my 1980 245. I bought mine at 125K and the previous owner had the clutch done at 115K (they towed a camper trailer). My car has over 300k now. Which color do you like better? Interior condition and material (vinyl or cloth)? 2 or 4 round headlights look better (my opinion) and give better light than the 4 rectangular lamps of the '83.
If your 1980 runs well and you haven't had to give the car up to the insurance company you have a lifetimes worth of spare parts for the fuel injection and ignition (and you are probably familiar with the K-jet system). The '80 probably has solid front rotors, the '83 vented -- but the brakes on either will stop the car just fine. The '80 may have engine wiring in better shape.
So--on the one hand--on the other hand. -- Dave