If I were wiring-up my tractor from scratch, and I had no existing 6V battery/generator already , I would go with an alternator, mainly because I like high power 12V accessories like LOTS of super bright lights, a 12V sprayer pump, and whatever other gadget I might like to hook-up. As far as points vs. electronic ignit., electronic is nice, but more expensive. Points work just fine and are very dependable. Go with a 12V coil, not a 6V coil with a resistor. But having said all that, I did re-wire my tractor from scratch but had a good 6V generator and 6V battery, so I stuck with a 6V system and oversized the wiring, all 12 gauge or 14 gauge with super fat truck battery leads to the starter. It's very dependable, but I can only run two 6V headlights without pushing my amp meter into negative territory with my meager 6V generator output, and the lights are not as bright as I would like. I'm waiting for my generator to burn-up to give me an excuse to convert to 12V.... been waiting for 6 years now and that darn generator is still running fine.