Custom setting to determine "root URL"

Thad, Maybe you could use a custom setting (which is a sort of global variable stored in your org). Your pages could build the url’s and append in the value of the custom setting, in one case the setting would be “apex” and in the other “community name”. You can find custom settings under “setup/develop/custom settings”. You can add a model to a SKUID page that gets the custom setting data, just like it was from a custom object, and then refer to that model to get the value you need.