I installed a Cleanaire system at the time and installed the MB600-95 model heat exchanger but used a local HVAC installer to do the design and installation (there's also an annual service - mainly an inspection and filter change). It was not cheap and I think close to $10k although it would be more than that now - they also have a pretty low tech controller, no timer and it's essentially two switches (on/off and summer/winter mode with a dial for fan speed) which I have inside a hall cupboard but usually don't actually change settings except the summer/winter mode and may dial down the fan speed at night as opposed to the day.
http://www.cleanaire.co.nz/
http://www.cleanaire.co.nz/Products/CLEANAIRE+HRV.html
I went for the 95% efficiency heat exchanger rather than 80%. I live in Auckland and in a well insulated house but the hygrometer suggests that the humidity is well controlled and the house is warm. I also don't have massive heating bills - until we had children we mainly used a flued gas fireplace for the main living space and some oil column heaters on timers for the bedroom - but we installed and use heat pumps for heating with timers and wifi controllers.
The other system I looked at was this one - the Mitsubishi Lossnay although I seem to recall something about there was something about the exchanger core that I wasn't convinced about
:
http://www.mitsubishi-electric.co.nz...ation/how.aspx