Rekordbox with setup with turntables and xdj 1000 mk2

Can someone please help me with the configuration of Rekordbox.  I have 2 PLX 1000 turntables and 2 XDJ 1000 MK2, with a DJM 750 MK2 mixer that I want to use all together.  I can get the 2 turntables working on channels 3 and 4, but cannot get the xdj's connected, sometimes i can get one to work, but if i close down Rekordbox and open it again it doesn't remember the setting.

Hoping someone can please give me the steps to getting everything working together, and it remembers next time I open Rekordbox