Year One Engine forward Harness

I was looking to change the engine harness and looking at Year one it has two different harnesses. The stock replacement and a modified harness. It looks like the modified is used for the electronic voltage regulator and the electronic ignition. I was going to modify my harness for the elec regulator but I do not have the electronic ign set up. I'm using the stock setup with a MSD distributor. Besides having to buy the electronic ignition module what other modifications would have to done,and how would it work with the MSD? Should I just buy the stock harness and not worry about the electronic ign module and just set it up for the elec voltage regulator. ](*,)Thanks in advance