I would stick with factory. There is www.mercruiserparts.com I have never purchased through them, but I believe all the parts are factory and they have a nice website. Maybe someone can comment. They are an advertiser here (Bam Marine).

For a new cap, rotor, spark plugs, wires and a 6-pack you are probably looking at $150-$175. Not bad.:drink:

You shouldn't need plug wires. Just inspect them for cracking first.

I use merc caps and rotors. Get the spark plugs at an automotive store. I prefer NGK's. NGK Part # is BR6FS stock #4323. BTW, I have 2000 502mpi's as well.