1994 Saturn SC1 Possible Distributer? Which part do I need?

Hello.

I got this problem that just started pretty recently and it has gotten worse over time. The car has been starting really rough, runs rough for a few seconds and then runs just fine. Now after it has been sitting for more then a couple of hours it sometimes takes a few trys to get it to fire and then runs rough for a few seconds.

Whenever you put a bit of a load on the engine such as accelerating rapidly or going up a hill the car will spark knock pretty badly. We tried several options such as spark plugs, wires, fuel injector cleaner, air cleaner, and even burning premium. We had a mechanic tell us it's a possibility that it may be the distributer. I went online to check on some pricing not realizing that there are all these choices for parts for the distributer and the whole distributer itself. I'm pretty sure it dosen't need the whole thing so which part would be the best option for me? Here are the options from the Advance Auto Parts online store:

Distributor
Distributor Bushing
Distributor Cap Cover
Distributor Cap Gasket
Distributor Cap -Perf.
Distributor Cap/Cap Kits
Distributor Cap/Rotor Kit -Perf.
Distributor Components -Perf.
Distributor Gear
Distributor Lead
Distributor -Performance
Distributor Plate
Distributor Pole Piece
Distributor Rotor Button
Distributor Rotor -Performance
Distributor Vacuum Advance


Any advice is well appreciated. Thanks a lot.

Regards,
Cameron Black