I tried setting it to various other values (WindowsLookAndFeel, MotifLookAndFeel), but couldn't get Eclipse to recognize any of them
You shouldn't need to do anything special. I used the following:
// UIManager.setLookAndFeel(new NapkinLookAndFeel());
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
Also it didn't compile with the MoodyBlueTheme so I just used the OceanTheme. It workd fine for me.