There are five major TurboHeads:
#1 - #4 will interface with the 8X adapter collar & the adapter collar for the 8AX/8NX.
I am sure you can buy these adapter collars from SureFire (give 'em a call).
The N5 lamp works in all the TurboHeads.
Therefore, any of the four TurboHeads and the N5 lamp will work with both the 8X & 8NX/8AX, but the adapter collars are different.
The TurboHead kits:
T5 (has N5 Lamp & #1 TurboHead)
KT5 (has N5 Lamp & #4 TurboHead)
Al