My friend Lyn French has been running the same EC2/EC3 system as I have and he eliminated the second mag a couple of years ago, so I figure it's time for me. According to Lyn, I just need to add a second set of coils, hook up some wires and I'm good to go. Naturally, easier said than done.
Here is a photo of Lyn's installation of the upper spark plug coils. He ganged the four coils together and mounted them of top of his plenum. He was able to do this since his plenum doesn't cover the whole crankcase.
Here is my plenum setup. Notice it covers the entire crankcase since I wanted to provide as much cooling as possible. Since there isn't any room left in the engine compartment I'm somehow going to have to figure out how to mount the coils under my plenum.