If it has a name that doesn't contain the words "Sci Fi, Alleyway, Hallway, Generic, Modern, Futuristic, Doorway, Tunnel, then your probably pretty good.
ctrl+click to convert selection to UVs, then to selection boundary and then to edges->contained edges. or you can make a mel shortcut: ConvertSelectionToUVs;SelectPolygonSelectionBoundary;ConvertSelectionToContainedEdges;
My way of doing it : + be sure to have "reference containers" option enabled during the export as an FBX file. Otherwise the UDK will not read the hierarchy correctly.
Working slowly on props for the scene! I plan on making several variations of things the crates can contain -- meat for the carnivorous creatures is the first on the list. :)