This is the ignition you want to buy and it is available from several sources
http://www.agaperacingandhobby.com/v...?productid=163
But you will need to get someone to make an aluminum ring to go around your prop hub to hold the magnet and an aluminum bracket to hold the sensor as in the picture above.
Here is the RCEXL 1/4-32 spark plug
http://www.agaperacingandhobby.com/v...?productid=172
Here is the 120 degree 1/4-32 boot kit if you are converting a different ignition
http://www.agaperacingandhobby.com/v...?productid=299