On the southern side of the mountain there is also:
Waiouru
http://www.aip.net.nz/pdf/NZRU.pdf Karioi non AIP
Ohakune non AIP
about 10nm to hte south west is Raetihi also non AIP.
Hope this helps, I hope to get down there myself soonish so do tell me how it goes.
Niner