Not sure about what exactly constitutes the *required* gauge and pitch, since there are many setups that would work. So long as your bar and chain are matched as to gauge and pitch, and your sprocket is matched to the chain and bar with respect to pitch, you should be fine.
An 024 will likely be happiest with .325" pitch chain and a 16," which would require 67 drive links for most bars of this size; it would be even happier with a bar shorter than 16" if you can find one. Around here Stihl likes to sell their .325" stuff in .063", but it can be had in .050" or .058"as well. Which gauge you settle on is up to you, but it is usually best to stick with whatever is most widely stocked where you live.