Buy any branded oil and change it at the correct service intervals and you will be ok, i use a 10/30 semi synthetic with no problems. No need to go for Mobil 1 or any daft priced oil, pop into Halfrords and pick up anything thats more than a tenner and less than 30 will be fine. There is a lot of info on the packaging about oil specs but I think you will find that any branded oil exceeds what the manufacturer recomends for your engine.
Steve.