Will you have the time to wait a couple of generations if you want to breed your line of guppies or the Endler's? If that is not a goal you might have, keeping them together is not that big a deal in a community tank.. If you were going to save fry, there are ethical issues as to what to call them and whether to sell or give them away.

You may have seen my diary mentioning that Endler's article in the November TFH. If you are interested in it, check with your local library. If they don't have it, they may still be able to borrow it from another library.

By the way, neons do better in the low 70s. White clouds also will do better in the low 70s (or high 60s) than at warmer temperatures. They will live at higher temperatures, but their lives will be a little shorter.