These are two names I have never heard used personally until now. I was recently introduced to a guy named Casper; now, I always had a soft spot for this name, but I could never imagine it on an actual person, but when I heard it I thought: 'wow, that's really cool!' I guess it may have helped that the guy was an all round pleasant person.
Bianca, on the other hand, is a name that I never liked and despite meeting a really pleasant woman by that name recently, I still can't get along with it. I always thought it sounded a little harsh.
:0)