What about looking into the Hydor line. They make good skimmers for the nano world. They are an in the tank skimmer. Two models: slim skim nano and the original slim skim. They are sleek, small footprint and I hear they skim really well and release no microbubbles. Mr. saltwater tank does a great review video on this skimmer at this link:
http://www.youtube.com/watch?v=zA9dDnQbx3s
hope that helps.