Well, in site 3, if you have 12 DC's spread out amongst your campus, and you have 12 subnets available, then the only way to do this for 2K clients is to put each DC on it's own subnet and create a Site for it. Now, you mention that most of your clients are Win9X. I believe that the Directory Services Client allows for Win9X machines to choose their DC without having to create sites....have you checked that out?