1. MR-03 can be use MM, RM, LM but no MR. The major different is the motor mount. Player need to change the motor mount to fit the body. Check this link: http://www.kyosho.com/eng/produc ... l?product_id=105671
2. Futaba 4PK is build-in Futaba 2.4GHz system, it is no connector for module. Someone do the internal modification on 4PK for Mini-Z.
By the way, do you know what you want to know? If not, go to the TRACK and see what you need...
If you haven't any remote control and need to buy the new one, buy KO-EX1 or EX-10, cos its no need to modification the module and it can directly install the KO 2.4G module.