NZ is lucky to be a significant way through rolling out Fiber to the Home a nationwide scheme called "Ultra Fast Broadband". I don't know how far along Ashburton is but Christchurch has the highest percentage deployment last time I checked which of course is pretty close.
Most houses will be 100Mbps download and 50Mbps up to start, I think you can chose a slower option. Higher speed are likely in the future thanks to the technology NZ chose.
UFB prices are still expensive but dropping. I am aware of a provider (Orcon) now offer a VOIP phone line and unlimited data for $99 a month, I have friends on it in Christchurch that taunt me with there connection superiority.
DSL2 is likely available if UFB isn't yet, and of course its hard to quote speed as it depends how far from the exchange or DSLAM you are. Likely to be anywhere between 4-20 Mbps.
While I am on the topic........ may as well have a rant.
NBN vs. UFB head to head comparison
Now NBN here in Aus is being reduced to copper for the last mile, the gap is going to be far worse than the above link and Australia is about to enter another decade of abysmal internet. This new infrastructure government doesn't seem very infrastructurey, is that a word?
/end rant