What ignition should I use???

I agree with Rusty, and others. I have owned several cars with point distributors. Some would rev deep into the 6s without issues. Almost every spring though I would have to clean the points, so it would start. It seems the points would oxidate to the point of no start during the winter storage if the points happened to be open. I have seen this on all kinds of farm and recreational equipment as well. I say leave it, but be prepaired to clean them now and again; no big deal. Ok so I thought about it a little more; for you it might be a big deal on account of the dist. being about a mile away from no matter how close you will be standing beside the car. As to the cap moving around, no big deal either; it doesnt usually affect anything. Sometimes I have improved the clip clamp by bending them. A dualpoint would be a good option as its highly unlikely to oxidate both sets of points during storage. And the oem dist usually has a stronger clamping force on the clips.
The factory ecu from a 70 up could be mounted inside the cab.The ballast however needs free air movement around it to prevent overheating and/or setting nearby stuff on fire. The ecu absolutely needs grounding.