Minimag will do a small coil and also a box of tricks so you can trip it with a Hall Effect sensor.
If you do go with the Galloway then the ignitor needs a low tension coil which can be obtained from an old strip light fitting.
The CDI units from S&S also get good reports, again these are Hall effect triggered
You can also build one with a small motorbike coil sourced from e-bay, these can also be made to make a buzz coil ignition if that is what the engine calls for.
J