How far has the car gone ?
My previous car had gone a fair distance and the thinner oils would disappear, nothing excessive but between oil changes it'd prob take an extra 1.5 l.
Here is a site with a little information about oil viscosities but as bonestock said the 5W30 should do fine.
Car Bibles : The Engine Oil Bible
Judging from your list of oil it looks very much like the biltema oils, and I have used found them to be quite alright, although now I buy oil over the internet, where I can get a premium oil with postage for about the same price as a lower midrange oil in the shops.
Opie Oils - Automotive Fluids, Oils, Parts, Tools is the company I used last (and will use again), their prices are about the best, they will actually post abroad and they have a wide range of filters and oils. Delivery was awful though as it went with UPS and I ended up having to go to their terminal (40km away) to pick it up.
Haven't really listened to much of Kent's music, shame that they are finishing though.