This should be included with Rubicon by default if you ask me.
This is a heavily modified version of the XBLA Rubicon HUD that was posted by Nobility some time ago: http://simplici7y.com/items/xbla-rubicon-hud
The interface graphics have been replaced with proper ones from the old Rubicon HUD and all the weapon graphics have been recreated in HD.
Go check it out.