I agree, pearl danios are the best. I have 3 pearls (used to be 4 until a loss in the family occcured) in a 10gal with 4 cories. I have never had a problem with fin nipping (IME danios are less agressive than zebras or leopards). My pearls also spend as much time in the middle of the water column as they do the very top. Any zebras I've ever had just stayed at the top.
Good luck with whatever you choose!
Good luck with whatever you choose!