Thanks for the advice everyone. Based on everyone's input, I'm planning to go with:
Betta
Clown Pleco (or Bristlenose if I can't find one)
6 Cherry Barbs
6 Harlequin Rasboras
I would have liked to have added 6 glowlite tetra too for variety, but I don't want to overload the tank, so I'll just...