To me this seems it wont work, why ask or take in applications for Gym leader's? Most site have a Gym leader tournament where the people who want's to be one enter's and usually the top 4-8 (depending on how many you want to have on the site) should be given the GL spot's. This make's the decision appropiate as the strong battler's get to be GL's decided by a tourney which is better than choosing people to be one where they could not be as good.