Hello from Morocco
maybe you can duplicate a moodle/lib/editor/tinymce
rename it to full_mce and another duplicate to be renamed to small_mce,
then (optionally) drop the tinymce installs from tinymce.com onto
moodle/lib/editor/tinymce/tiny_mce/3.x.x - in case you want to really go deep at tweaking the editor.
and change the info at the full_mce and small_mce folders
moodle/lib/editor/full_mce/tiny_mce/version.php
$plugin->component = 'editor_fullmce';
moodle/lib/editor/small_mce/tiny_mce/version.php
$plugin->component = 'editor_smallmce';
Keep in mind that the next time you upgrade moodle, to avoid overwriting these custom tweaks, you have to remember these steps, unless you upgrade moodle from svn or by using rsync command.