Bianca is my sister's name and I actually really like it as a name, it's uncommon but not unusual. I find it pretty.
Blanche on the other hand is very surnamey and sounds rough to me. I don't like
Blanca either, it sounds like you're trying to say "blanket" rather than a name. I'm pronouncing
Bianca as bee-ANK-ah (I'm Aussie).