I just replaced my old cap rotor, etc. with Oem parts and the entire assembly (distributor, etc.) cost me 500 $. I'm not sure about the quality of the 3rd party components, but my car feels almost brand new with the oem replacements. And if you are talking about after market ignition setups, like the MSD box, etc. you still need your original ignition assembly to run them ( they are simply add ons). The only thing you might want to change, is the cap (you might want to get one with an external coil instead of internal). Finally, like styleteg said, you dont really need MSD etc, unless you are running a serious setup.