Thanks for all the suggestions! Things are starting to get redundant.
I have corys already and right now I don't want anymore. The bottom of the tank is busy enough already, so the same goes for clown loaches (plus they just get too big)! I already have zebra and yoyo loaches.
I don't really want anymore barbs because they spend too much time near the bottom of the tank.
Do you really think the black neons would get eaten? They're sold pretty large around here, and they look too big for my angels to eat. The angels really aren't that big. As far as schooling/shoaling, the angels, while not aggressive (they're very curious about everything!), are nosy enough to get the blackskirts to school once in a while.
I've got another tank with livebearers (guppies and platies). I keep the pH in the community tank pretty low (6-6.5), and from my experience with guppies, I don't think swordtails would do so well.
I think rainbows are just too expensive around here, but I'll recheck the price on the threadfins. Those're the only ones I really care for. But don't they like a higher pH?
I like the serpaes, but I've heard they're nippy. Any experiences?