I know the AEM have an ECU for the FD3S, Does anyone know if they either offer one for the FC3S or if the FD model can be used with some AFM modification?

Reason I ask is that I like the AEM interface and I'd like an alternative to Microtech or Haltech.

 

Post the question on the AEM forum, you might have more luck there. I have the FD3 AEM and know you can change all the parameters. I have a lot of mods and didn't have a problem to adapt the ECU.

 

AEM currently only has PnP EMS for the FD. They do have generic EMS that can be used on any car, but you will have to know how to redo the ecu connector