Brand is your choice, I go with Castrol gear and diff oils. Engine I choose Mobil Super 3000 FE
Gearbox on the 2L 6 speed will take the 2 litres, slightly less on the 5 speed.
Diff on all just under the 1 litre.
Engine, buy the 5 litres 2 L takes around 4.6 ish litres.