I am a fan of scissor tail rasboras. I think they would look great swimming around the bottom of the tank through your log and some neons up on the top. Maybe a mixture of regular neons and black neons....IMHO....
Maybe six neons and a couple cory cats for the bottom.
Whatever you do, remember schooling fish like tetras and danios should be in at least a group of 5 or 6.
Try to spread the fish out over 'levels' of the aquarium. Bottom and top.
Tiger barbs get a bit big, like to be in groups of 5 or more and love to swim. I would really think a 20 gallon would be best for them. Tetras that stay under 2 inches are the best bet. And in a small tank try to stay with only one schooling mid level swimmer. Too many and it just gets messy looking.
Thanks for all the input....keep the ideas coming.
I may be leaning toward the apisto with some other dither. I want an active aquarium. Something fun to watch. That's why I was thinking tiger barbs. I was hoping 4 of them would be enough to feel like a school.
The bottom of this setup is pretty crowded with the tree root piece and plant. Is there enough room for bottom feeders?