I will be in ChCh this summer and will be shopping for a 4wd. I've done a little searching and it seems like Trademe or Turner's auctions would be a good place to look for a new rig. I am considering a diesel powered rig like a Surf, Terrano or Bighorn as I will be looking at a daily driver that can handle some light to moderate offroading or camping. I don't have any experience with diesel engines and was wondering if you could recommend a mechanic in the area to check the engine on a potential purchase, and possibly other sources for a clean used truck?
I have actually owned Nissans, Toyotas and Isuzus and liked all three, so I am looking for the one with a diesel engine that is the most reliable, doesn't necessarily have to be the strongest. Relatively quiet and non-smoky would be a plus.

And of course I'm always willing to mod it to gain a little more power and/or reliability. Thanks for any suggestions.