Hiya Rich,
If its literally just an oil and filter change, have you considered National tyres? They have a deal on oil changes and you can get another 10% by printing off the voucher on their website. They use Castrol Edge 5w 30 and the price includes filter. The cost is cheaper than what most people can get 6 litres of castrol edge for!! I think the oil change came to £35!
Tip - remove your under tray before sending it in (they may charge a surcharge for removing the under tray)
Pick up up a new sump plug from the stealers and get the guy at national to replace the old (otherwise they reuse the old one).
When i took mine in, i watched them like a hawk as they worked on it and didnt have any problems. they drain the oil from the sump rather than sucking it out with the machine.
Hope this helps
Rich
You might get a recomendation to change tyres/brakes etc but its just a recomendation.