I would suggest spending some more time researching and spending time talking to actual fancy owners and breeders. Fancies are certainly not 'beginner' fish despite the impression many stores and internet sites may press upon the public. Fancies actually require more work, commitment and care than the larger majority of tropicals.
I would honestly suggest waiting a year or so and see how your present orandas develop. Orandas have one of the largest growth potentials of fancy breeds and you may find that they are pushing the limits of the 50g in the future. The present world record holding fancy is an oranda named Bruce that measures over 18 inches. Please do not hesitate to ask questions!