I don't know about anyone else but this is how I got my avatar from between pages 2-4 of the list:
In Edit Options, click on More Info.... on the left hand side under Avatars. The entire list of system avatars comes up.
Choose the one you like and right click it and choose Properties which will show you the internal URL for it.
Copy and paste that URL into the Avatar URL textbox in the change avatar screen.
Ta da.
