msd ignition

I have a question for the knows of everyone here. I am building a car for my wife to run at our local track. 1974 Dart Swinger, it will start out with a mild 318/727 combo 8-384 with 4:10's. This will let her have some seat time and get used to the car and the routine. Later, after a year or so I will step it up for her so she can go faster hopefully mid to high 10's. My question is this, what distributor and ignition combo do I get now that would work for both. I really don't want to have to purchase one now and then too. Any ideas ??????