A simpler, easier, and likely less expensive option to improve firing, would be to install NGK Iridium plugs in your bike. I went that route, and the engine started as soon as the switch closed. With the regular plugs in place, I had to grind the starter for 3-5 seconds, rest, then hit it again, to start it up.
A second option is to use GM automotive coils, which pump out much more energy than the OEM coils. Don't know the details, but I remember folks stating that the coils could be found in junkyards, for around $15 each. Cheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII