Some points to consider in buying a wok
Generally, woks range in size from 10 inches to 16 inches. The 14-inch size tends to be the most practical. Woks are made from spun sheet steel, hand-hammered iron (low carbon steel) and stainless steel. A thicker gauge metal is preferable to a thin gauge as it will conduct the heat more efficiently. The disadvantage of stainless steel woks is that they do not conduct heat as well as traditional woks made from uncoated carbon steel and, though they might look more attractive, you have to use more oil in them to prevent foods from sticking. Teflon-coated woks are easy to clean, but cannot be heated to high temperatures without damaging the teflon.
If you have a gas stove, you can use either a round-bottomed or flat-bottomed wok. If you have an electric range, the flat-bottomed style is the best choice because it sits directly on top of the element. If you buy the right wok, you won’t need to use a ring stand.
There are shallow concave woks and deep concave woks. The best design for a wok is a medium-concave wok. If a wok is too deep, the heat will be concentrated in the bottom of it and not enough on the sides. If the wok is too shallow, again, only the centre of it will be heated and sides hardly at all.
It is better to buy a wok without wooden or plastic handles because at some point you might want to season it in a hot oven. (see Seasoning A Wok.)