electronic ignition is very popular for RC gassers. There are several units for sale from independent manufacturers. plus many new engines come with electronic ign as a standard feature. the 1400 mah battery pack is about right for a 2-cylinder engine. Two cylinders take more power of course to drive 2 spark plugs. My pack lasts for many flights - perhaps 2 hours of continous running time. It is also a function of the rpm of the engine. more rpm equals more sparks per second. Most ignitions are powered by 4.8 or 6.0 volt packs. So 4-cell or 5-cell AA battery packs work fine. For a single cylinder engine, you could probably get by with 800 mAh.