Diff - Castrol Syntrax Limited Slip 75W 140 3 litres for both front and rear
Trans fluid - I like Pentosin FFL4 Racing (powerenhancer.co.uk £355 but you can get discount codes from them for at least 10% off). You only need 8 litres for a change so you'll get two changes from a 20l tub.
Engine oil - Always fully synthetic - Actual choice can depend on mileage of your car and whether it gets tracked i.e. whether to go for 0W-40 Mobil 1 as standard or maybe 5W50 Motul Sport.
Check out the forum sponsors Opie Oils as there may be discounts to be had.