Just fitted the Hondaman ignition to my 78 550 F2.
http://sohc4shop.com/catalog/product_info.php?products_id=32Not a true electronic system but an amplifier I believe. Retains points and condensers using the points as a switch. In the case of failure it can be returned to the normal set up in a few minutes, though Mark guarantees them for 5 years. Cost about $94 US shipped to the UK. Mark is a really nice guy and keeps you informed of shipping progress all the way. Makes lots of other nice SOHC bits as well (fitted his blade fuse box).
Fitted the box as per instructions, did the 3000 service,new set of OEM points, timed her up and the bike now fires first flick of the starter, idles smoothly which was always a bit hit and miss before.
Lots of info on Hondaman on the USA SOHC site. Works for me.
Bob