What is th best swordfish species for my situation?

I have a 20 gal tank, planted, with 1 male blue neon dwarf gourami, 3 red wag platties, 7 guppies, albino cories, and ghost shrimp!? And I want 2 females and 1 male swordfish. Wat is the nicest one? The tank has a lid, and eventually I want to get 5 neon tetras. Don't tell me it's over stocked either. Or anything like that! I just want to no wat is the best swordfish tank mate to go with my male dwarf gourami, guppies plattys, shrimp cories and neon tetras in the future!!!!! Thanks in advanced