Guys, I don't know if he is still offering it but SDSEFI (Simple Digital Systems,
www.SDSEFI.com) has both an ignition only system and a full engine management system that will work for a 13B. His system doesn't have split firing, but most people running a high performance rotary do both plugs at once anyway. He has a newer dual in one box system, FOR AIRCRAFT that could be run simultaneously to do a split fire and be fully redundant.