I want to have 2000 sites in my network in wpmu. The sites are divided into categories and according to the categories the header and footer would change slightly, i.e., color, header image and footer image but the template should remain the same. Also, I want it to be done by making change at one place only and if possible by using some GUI like wordpress admin area where user gets option to change the header image, color, etc. Is there a plugin for the same. I looked but couldn't find anything or will I need to code something in php?
Could someone please help me with this?