its best to get all the bits listed mate. I got all mine just before xmas. I personally i would change the oil & filter again as they have to drain this. Also make sure you get some G12 coolant as Nick normally washes himself in it whilst draining the car.
All in all i think the total came to roughly £100 inc oil, filter and 2 bottles of G12. I'll dig out my receipt later on as i know some of the part numbers i quoted had been superseeded.