I don\'t believe anyone has tried to run CS via x-windows on a Mac, although it\'s possible. To do so, you\'ll have to configure crystal space specially.
Probably better to start off using the normal (cocoa based) plugins! Like Cha0s said, following the build guides is a good idea, you might need Fink or Darwinports or both to get all the libraries you need.
Good luck!
Daniel