Thanks @David-TP The price of the TL-WPA8631P kit is quite a bit higher in NZ. PB Tech, which usually has competitive prices, has the kit at the equivalent of 145GBP and with the WiFi on the nodes...

I bought a TL-WPA8630P KIT (one 'master' and one 'node') which is working OK but there are areas of my home that are still not covered by the WiFi (which seems to have quite a weak range on the Node...