To save you an extra 30 minute drive, you could deal with Andy Smith in Levin.
The place is called Smiths Automotive. Just recently had a cert done by him. He's really good!
Same with you Kevin, just go back to Andys
Recently had mine changed not long ago. I used Motul Motyl Gear 75W-90. Takes approximately 4 litres.
If you're feeling rich, Motul Gear 300 is the other option (full synthetic), but pretty damn pricey.