I agree that it sounds as if the coils are dying on your bike, rather than the ignition. I would test the coils under heat stress.
If you are fitting an aftermarket ignition follow the manufactures advice on choice of coils, HT caps resistance etc etc and make sure that the system is reliably grounded and that parts such as the ignition switch and ignition cut out switch don't intermittently lose contact under vibration. Otherwise you might end up chasing your tail all around the world and end up blaming the ignition manufacturer.
I have used ignitions from Silent Hektik, Sachse and Boyer, all have worked well. I would not use an ignition that mounts its "black box" inside the engine, because it puts the components under unneeded stress from heat and vibration. Away in cooling air is better even if it's more difficult to fit.
1070 BMW R90s replica