For *exactly* the functionality you are asking for, being able to control the visibility of a menu item based on a user group, you might want to search for JUGA (Joomla User Group Access). I think it's about $50, but included with the package is a replacement for mod_mainmenu which allows you to restrict particular items by group.

You can achieve something similar with MetaMod, but in a different way.

You would need to set up 2 separate menus, one with the gallery and one without the gallery. When setting up your second munu, it's best to make all the menu items into "aliases" of the menu items in the original menu, rather than brand new menu items. This is so that the URLs from the 2 menus are the same when using SEF URLs (otherwise, you'll get completely separate URLs depending on which menu is active).

Once you have the 2 menus, you have 2 separate "modules" that can be displayed in the module position.

Then, you set up a very basic rule in MetaMod to switch between the two modules depending on who's logged in:

if ($user->id == 1 or $user->id == 2 or $user->id == 3) return 101; /* module id for these users */
else return 102; /* module id for all other users */


replace 101 and 102 with the real module ids for the two menus.

Hope that helps,
Stephen