hobby5 said:
Sorry for your loss!
Imho your tank is too small to keep any of those small danios or characins.They are very active swimmers and should be kept in groups of 10+. Moreover if kept alone (meaning only this species, not a single fish) they tend to be very shy and skittish. My favourite in such a tank would be Neoheterandria elegans or Heterandria formosa. Even though they are live bearers they don't reproduce as rapidly and if u have surpluse there is always demand for it.
In fairness, the Dwarf Emerald Rasbora and Celestial Pearl Rasbora aren't nearly as active as other danio species, such as the zebra or pearl. I'd certainly have no qualms about either of those species in a 10gal, and indeed have kept CPDs in a tank slightly larger than 10g. The generally accepted rule of thumb, certainly in this corner of the interweb, is that shoaling species need 6+, although I would agree that the bigger the group, the better.
I've kept both CPDs and Chilli Rasbora in a small tank, and didn't find them skittish at all. That said, my tank is very heavily planted. The reassurance of a place to hide gives them the confidence to come out into the open. In a tank with little or no plant cover, they will all just hide up at the top corner, because they know they have nowhere to hide if they were to encounter a predator.
Personally, I really like rare livebearers, and second your suggestions - the only problem is finding them initially in an area local to the OP, and secondly, rehoming the offspring locally. There isn't actually a huge demand for them - your only hope is to other specialist aquarists, and there may not be many or any of those locally to the OP. The OP may not want to get involved in the rigmarole of sending fish long distances.