Very nice truck!!! SO, the good news, what you want to achieve is most definitely doable! The bad news is that it will take some modification to the chassis plates...
You need to find a way to attach the RCM Universal Mount to your bottom chassis plate. A good friend did a similar mod to his G4 using a RCM Universal Mount, and he used a modified Hardcore Racing Titanium Centre Skid. They can usually be found pretty easily on ebay, if you want to send me a PM I know someone who has quite a lot of HCR stock and I could most likely find you one pretty easily... Here is a pic of Travis's G4:
Travis used a Spider 8 centre diff with 46t, so you will see he had to modify his top plate to provide the required space for the spur. Depending on what tooth count you go with on Mike's Slipperential, you will most likely need to do the same...
Are you confident with working modifications like that? I know I am not haha, but I could put you in touch with a guy who could provide that type of service for you if you needed it... ;-)
Sammy
Emaxx 3908L, Gorillamaxx G4 with UE VBS & Widetrac, Gorillamaxx G1 with RC Monster Slipperential, Centralemaxx Ph@ntom, FLM Savage, TTR Centurion LTD, TTR Tremor, TTR Ripper Pro, GMADE Stealth