[Synchro909]

Hope I don't forget something but here goes.
You'll need a battery, 12v alternator or generator, ignition coil (or ballast resistor), a few light globes and I suggest a resistor each for the horn and windscreen wiper if yours is electric.
When I converted, I changed the field windings in the starter motor around so they are all in series rather than a combination. A kit is available for this but I do my own using the original field coils. This results in 4 times the resistance in the fields, thus reducing the current getting to the armature and slowing it down. Many say that the starter will be fine as is and I have seen many that have - for a while. I took the safe route. Another way of slowing the starter is to use small gauge battery cables so you lose a few volts in them.
It's not a big job and you can get replacements anywhere when needed.