Actually you can get induction wok burners which are concave and fit any old fashioned (i.e. iron containing) wok and work VERY well. As well or better as the traditional high heat gas burners. Ours are from Cooktec

Gaggenau also makes one that is flat, but can take a round bottom wok "floating" on ring because of the way the inductions elements are set up there. Gives you flexibility to cook proper round wok, OR a flat skillet or stockpot.

Yes, I guess it depends on whether this will be your only cooktop. If your primary interest is in wok cooking, though, the concave is definitively superior to cooking in a flat bottom wok on a ring. Th concave cooktops are for serious Chinese cooking and one of the cool things about them is that the handles of the iron-containing wok stay cold to the touch no matter how hot the wok is.