I keep my female with guppies and danios and she's fine, you could even keep 2 females together in a comunity tank (just no males) then keep a male seperate? My male is in a small tank with one silk plant, small filter (similar to the one pictured above) and a heater, he seems happy. Corys should be fine with a male as they tend to hang around at the bottom and keep out of the way (so lots of room for beta to swim around. Corys like sand rather than gravel though so you might want to think about this before setting up a tank. My comunity tank has sand but i havn't added corys yet (still looking to get some).