Unless they put one of our major tracks out of commission for close to two years it is going to cost tens of millions to create one new track. The extra costs being supporting infrastructure like stables, stands, etc.
So a poly sand track is the most likely option inside an existing turf track. Not many candidates for that option and I don't think our NZ trainers will embrace that type of track.
Strathayr would be best but I doubt we have the management skills and they don't last forever. Does any club actually return enough revenue to maintain them?