I have a Dalmatian LyreTail (she's pretty) and a regular Dalmatian Molly.
What you could do, is add some Guppies. They are very pretty, and don't get overly big. You want a 3 to 1 female to male ratio if you want a good shot at reproduction.
If you want to go with tetras, try to keep them in schools, I always recommend 3+ or it gives them a chance to be eaten by your more aggressive fish.