Fired off an email today to Gary Fisher, the NZer looking at doing the composite fins in Nelson. Hopefully he's still interested in doing some, his work is top-notch. Here's some of his spearing/freediving fins:
http://www.ronsseacorner.co.nz/fins_garyfisher.htm
With any luck, he'll be able to get something going down here. If not, Keiran from
http://www.monofins.co.nz/ imports LeaderFins gear, so I'll have a chat to him about what it would cost to get a few pairs over, maybe a bulk discount would work.
All these guys specialise in finswimming and freediving, so they're used to customisation, plus most Specialfins, WaterWay (eg. Nemos) and Leaderfins can be fitted to any of the standard footpockets. Beware though, footpockets are NOT cheap. Locally, you're looking at NZ$120-$150 for each

. Luckily, places like
http://www.scubastore.com will do them a heck of a lot cheaper, just buy in bulk (or pick up some cheap spheras on the way out) to save on shipping. The best in the business are the C4 Mustang footpockets (
http://www.c4carbon.com/eng/sub/mustang/art.htm), but be prepared with a deep wallet, you'll have to pay through the nose for the pockets, then customise the blades to fit them.
I'll update when Gary gets back to me.