Hey Alex,
I'm on the Gold Coast, and hail from NZ. I never really kited in NZ, but from holidays over there, I've found that Mt Maunganui (Tauranga) definately gets the seabreezes more than any of the other areas I've explored on that Eastern coastline - plus, that area has a fair amount of other cool stuff going on, and is a hot destination for tourists/locals alike. As far as consistency - I couldnt tell you, but all I can say is that whenever I was there, I kited. (20kts, 2-3ft swell).
As for the Gold Coast ,yeah its OK, but nothing amazing. We have waves and lagoons/river mouths to kite, we get fairly consistent wind in Summer, 20-30kts, but more so in Spring. IMHO, Brisbane wind was much more reliable and consistent. The GC seems to get the random sea breezes out of no-where, so my only observation is on the Coast, you need to be ready to go, rather than in Brissy, I could rock up to the beach at 4pm and almost gaurantee some kind of a seabreeze, 3-4 times per week. But, no waves, obviously, being in a bay.
All places, GC, NZ, Bris, are great places to live, good facilities, good lifestyle, good people, and have better access to the world. WA is fairly isolated, depending on where you need to travel, but has its good points too. The wind is obviously a lot better over there....
GC climate is probably closer to where you are now - warm in winter, and hot/humid in summer. It's more vibrant than for instance Tauranga NZ, more to do, more clubs/bars, a lot more international events, a lot more tourists, etc, and the women arent bad either.... :)
Let me know if you ever end up on the GC, I'll take you out to Main Beach.