The RX-8 sensor is magnetic reluctance.  Same type, size & shape as the 3rd gen.  In fact if you have a 3rd gen sensor, you can use it if you can mount it correctly.  The Subaru sensors will also work but they are poor quality (many failures reported) so don't go there.

Tracy, I hope you know the answer to this question. Does the reluctance type sensor need a magnetic wheel to work? If the sensor has the magnet and a coil of wire might the pulse be made by any electrically conductive material? I am not an EE, rather a ME so I may be showing my "little bit of knowledge" but if I remember the theory you should just need a conductor to "cut" the line of magnetic flux. The use of a aluminum tooth wheel wouldn't save much weight but it would be nice to not have to paint it to prevent rust!

Bill Jepson