When considering Electronic Ignition for the SIII there were 2 main options.
The cheap option was to get a transistorised kit from an electronics store at about $50 and put it together. This item retains the existing points, but uses them only as a triggering mechanism. The points don't carry spark and so don't wear out (the cam lug can still wear). I had just fitted LPG and thought that the brighter spark given by this system would lead to more efficient combustion. Unfortunately the assembled kit didn't work and it was not worth the extra money to get it diagnosed and repaired.
The expensive option was to fit Pirhana Electronic Ignition which uses an optical switch. I got mixed reactions from auto elec mates, but there was not much else to fit to a 2.25. The preferable option would have been to get a factory electronic distributor from a later model (good if you're using a holden motor). The Pirhana system eliminates the points, but does not give a super boosted spark. It does however provide a square wave form. As the slotted disc in the dizzy spins, the optical sensor switches the electronics, thus the power to the coil is either on or off. With the points the gap widens and narrows as the lug spins on the cam and the waveform is more wave like. According to the experts this gives a clean crisp spark and is optimal all the time ( whereas points are optimal when new and then deteriorate). The Ignition specialist also reckoned the electronics sensor handled dust and moisture better than points.
Theoretically the two systems can work together, but after the kit failed (or I failed to properly assemble it) I couldn't be bothered trying again.
I figured $250 was more than a life times supply of points, so left it at that, until my Land Rover got stolen. After the police recovered it and the insurance company wrote it off, I spent a fraction of the payout repairing / replacing all the damage and used some of the excess cash to treat my car to the Pirhana system.
Go to the following web site for an informed discussion on the subject
<span style="font-size:12pt;line-height:100%"></span>']<a href="http://users.mrbean.net.au/~rover/electron...size=24" target="_blank">http://users.mrbean.net.au/~rover/electron...size=24 ('http://users.mrbean.net.au/~rover/electron.htm<span style="font-size:12pt;line-height:100%">[/size)]</span></a>