The server and the GUI are separate components. As for great SVN GUIs, Versions.app seems to be the favorite.
Editing to add the following additional SVN apps:
http://ciaranwal.sh/2007/10/10/svn-plug-in-for-textmate (TextMate plugin)
https://www.smartsvn.com/
http://www.syncrosvnclient.com/index.html
http://www.zennaware.com/