Check the Ember Tetra profile, it will help you. But to short-cut to the direct question, all characins are better with plants and chunks of wood and/or branches.Well guess I'm not getting cichlids. Oh well. Time to do more research on Ember's, OMG they're gorgeous!! I'm going to try to get some driftwood tomorrow. Are Ember's best with plants or driftwood or does it really matter??
On other fish, a 10g is pretty small so you are bst with small fish. ET are fine. Corys on the substrate would be OK. A trio of the pygmy sparkling gourami could work.