Value of the MSD

Use whatever distributor has vacuum advance, although now that I typed that if you get a Programmable 6 box you can control the timing from that box so you wouldn’t need a VA.

So my answer is buy the programmable 6 box and use the MSD distributor. IIRC you lock it out and set up the curve in a table.

Thats what I would do, especially since you don’t sound like you have a distributor machine to actually make getting the curve in shape way easier.

Probably even better if you can get the engine on a dyno so you can load the engine and figure out what your engine really wants for a curve.