Call me crazy, but I think in a 300 it's doable, I would advise staying away from the monster aggressive ones (Queen, Undy, Blueline, even Clown)....If you were to do it, this is the list I would do
Male Bluejaw
Female Bluejaw
Pinktail
Black Hawaiian
Lei
Halfmoon
Huma Huma
Rectangle Huma (introduce those 2 together)
Niger
There would be some squabbles, but I think they could co-exist