I would go with VX dexos 2,but you can use Castrol (or similar) as long as its 5/30 C3.
There is a promo clip on youtube about dexos2. It is a good oil at very low temp.
I got 20L of dexos 2 for £69, as I do a high mileage and change my oil every 10,000mls.
You may need to go to a dealer to have your oil light switched off if its a newer vehicle.
Older vehicles can be done by the accelerator pedal method.
Masterfit had an offer of oil and filter change for £50. The filter on its own is £24. Give them a call and see what they can do. Try haggling as well, that often works.
As for fuel filter,I wouldn't worry if your service schedule is up to date.