There are an awful lot of killies, so don't rule them out on the basis of behavior of one. I've kept a few types of killies and the most aggressive I have had to date (Jordanella floridae) is a ~little~ territorial and is no danger to the Danio chopri and Endlers it shares a tank with.
__________________ Tanks everywhere, a well-stocked garden pond outside and a Horde of Flatcoated Retrievers  |