Only a suggestion...Why don't you get a G.M. 6 cylinder HEI distributor and the VG30 distributor and combine them to make one!
Use the lower part off the VG30 (shaft and gears) and the upper part off the GM distributor (Ignition module, trigger and Cap)...shafts can be joined with a roll pin!
I have two distributors that were converted on a '59 Studebaker V8 and a '52 Henry J 6 cylinder. Check out this web-site www.performancedistributors.com/index.html
Just make sure you have enough clearance with the distributor cap! Heck...if you can't source this distributor use a Chrysler unit or any pre-fuel injected model!