Personally, I would go with either a honey gourami or else 1 angel. If the angels pair up they get nasty to tankmates. If you are ok dealing with that, then I do think 2 angels would fit in the tank. Just so you know, some adult angels will eat glowlight tetras. Glowlights are big enough as adults that there isn't likely to be a problem, but some angels will still eat them.
Harlequin rasboras, zebra danios, purple passion danios all school around higher in the tank than the glowlights that you have, so they would be a good choice for a second school.