Here is some stuff from Mercury.

This looks like the best match for the rotary engine.
It combines the alternator with a high voltage supply
for a capacitor discharge ignition system.
It requires two trigger devices but a $17 ABS
trigger will probably work fine. That, we have handled
and the plate holding it can be rotated to retard or
advance the ignition and fuel injection timing.

http://www.outboardexchange.com/

Flywheels
Under 50hp     $95    
Over 50hp (except highoutput)     $110    


Ignition Components
Stators     $100    
    

Simple, light weight,engine won't quit if your battery
goes dead. Very reliable permanent magnet alternator.

The only drawback is the capacitor fires only once
when several strikes are better. I will work on
a pickax based MSD system with several capacitors,
firing one right after another.

If you can get along with only 30 amps or so you can save
the weight of a conventional alternator and maybe the
battery. Ideal for a carb system. You might still need
the battery for the starter as according to Tracy
the rotary is difficult to start by hand propping
through the gear box. I think it might start if you
put a glove on the prop tip and had several people
jerk on a rope :)

Just about any coil will work fine with a CD system including
RX7 2nd gen coils if you unbolt them and disconnect them from
the now useless igniter.

Paul Lamar