That the kickdown cable is connected is absolutely 100% essential - without it connected and adjusted properly you can kiss your auto box good bye. And quite quickly too. Don't forget the Oil cooler too !!
+1 - I think you need to do a little more research before posting - try the ashcroft transmissions site for one. or ask ZF technical - I always find them very very helpful.
Thing is, the brackets for the FIP are readily available, really easy to fit, and the kickdown cable is also easy to fit, and easy to adjust, both initially, and for your preferred driving style.
Wiring loom should also be connected, especially the start inhibit circuit - in fact, you may invalidate your insurance if you don't - and if they were to start looking and find "other stuff"... well, you can guess the rest.
reversing lights are always worth having, and you'll need to know if the centre diff is locked.