Hi Chris,
You don't actually need anything else unless you know other parts are failing, but I always recommend having the other parts upgraded while the gearbox is opened.
I would recommend this package instead:
1. 350z DE JWT Clutch and Flywheel Combo - £729
Comes with chromoly clutch pivot ball, stainless clutch line and stock bronze pilot bushing.
The stock Nissan pivot ball is made from a weak Grade 5 steel and after 10 years of use has a tendency to break when an upgraded clutch is installed. The chromoly pivot ball withstand the extra force of an upgraded clutch. The stainless steel clutch line is a must have upgrade for the 350z with an upgraded clutch. This eliminates the mushy pedal feel that 350z has after installing high clamping force clutches. By eliminating all soft points in your hydraulic system, it adds to pedal response, feel, and gives you a little more adjustability in the pedal height. A stock bronze pilot bushing is included with this clutch kit for the easiest and most trouble-free to install and run.
Would also consider:
350z DE Koyo Clutch Throw Out Release Bearing - £39
350z 05-07 DE Stop Tech Premium Clutch Slave Cylinder - £39
Hope this helps, any further question, please feel free to ask.