I use Castrol Edge and always buy the oil change kit from Opie Oils (the expert) at a good price. Run mine to 20k between changes given that I do quite a few long range motorway runs a month.
Do the oil changes and brake pads/discs etc myself - as I have 3 to practise on! Although I'm booked in at Stafford Audi next month for their very good value cam belt change (£275) and water pump (£80).