I recently bought a new coil for cylinder 2 on my car. Unlike your problem, my misfire started after car was warmed up and revving. The new coil fixed it. Sounds like you just swapped the coils around to see if the misfire changed to a different cylinder. Since you've checked the easy stuff yourself, I would take it to a good Indy and have them look at it. I wouldn't want to risk serious engine damage trying to troubleshoot the more complex stuff myself.