I would think that if you scan eBay and such (Gumtree) you may be lucky to source some used hubs - especially since there must be a lot of comparatively new versions in Australia. (TTRs are currently still available new)
If your funds stretch to new then all well and good - at least you will be assured of the quality then.
Can't help you on the hubs - sorry. The chance of finding a hub from another bike that has the same spoke pattern, bearing/axle/spacer size and the correct offset seems unlikely to me but let us know if you crack it!
yep they still sell it new here in australia,tho i think its the same 06/07 model.Iv now realised these no chance of finding used but cant find a yamaha or A/M web sit that sells them.