I have to say that I prefer Sofiya better. It sould always have the nn of Sophie or Sofi or Sofie, but I think that Sofiya (which is Russian) sounds highly cultured, will probably not become trendy. It's also a place name (spelled without the Y, it's the capital of Bulgaria.) It's easy to pronounce and doesn't look like a "typo-name" to me. Some combos are:
Sofiya Katiana
Sofiya Isadora
Sofiya Anneliese
Sofiya Beatriz
Sofiya Cymbeline
Sofiya Juniper
Sofiya Gisabelle
Sofiya Jane
Sofiya Ariadne
Like any? (: