I've gotten the same Fancie twice now, and yes, trading gems can be a bit time consuming, forcing you to wait another 1, 2, 3 weeks while you technically already have enough gems... but I feel that's part of what Fancies are all about. It's part of the charm, or the rarity, of Fancies.
I DO vote yes for another fur, after all (hint hint) there's still an empty Bengal-color-slot in the lineup.
Different sizes might be another thing that would spice up our jeweled kitties.