OK, well, I found a fish that fit the requirements - pretty, active and all seems to be well.
I've got myself an orange Swordtail and his lovely female companion, who is orange and white. He is still quite "jumpy", moving to the back of the tank whenever he seems me come near, so I think I'll get some more plants for him to hide behind.
They are quite lovely, he has a beautiful flowing dorsal fin and they regularly swim up and down together. Neither of them have bothered the neons.
Thanks for all the help and assistance, I'm really loving my tank now