I own both AE 12R6 and CRC cars, and you'll be able to make the CRC shock (PN 3290) work. To get a useable length you'll need to consider their shaft extender (PN 3296), or the stock R6 Shock Rod End should work as both shock shafts measure the same diameter. The CRC ball cups are the same size the R6 uses for the steering and damper tubes. If you decided to use the CRC shock extender, I like their #1231 Plastic Ball Cup.

Hit me up if you have any other specific questions, just be patient on a response as I have a new born at home, so it can be hard to break away and respond timely.