A wok should be made of Carbon Steel. Buy the cheapest and nastiest one you can find from the Chinese Shops... Also no Teflon..
The thinner the wok, the better the conductivity of heat distribution. Cast iron, takes too long and if cools down slightly, you end up stewing everything.
Seasoning of your wok is very important. Look it up on YouTube.
I bought a wok from a Chinese shop about 8 years ago. R160. Still going strong and better non stick than any Teflon pan out there.
Wasn't going to mention the carbon steel because of seasoning etc. but you are quite correct in that it's the wok of choice. Yuppiechef have a selection - the seasoning is holding me back because I've got 2 x carbon steel frying pans and my god I struggled.
One of the pans has become my absolute favourite - eventually.