All three things are important and good I cannot decide which one is best because you have your own way of thinking and maybe you don't want to involve let's say in coop, then you don't need S-Builder (just an example). But basically you can never be wrong if you have SO on TCredits because you can buy or win on auction both (IAHBE and S-Builder) and more TCredits so if you look it like this than you can choose TCredits as your SO.
