I would choose Sana or Diana.. or plain old Anna.I'm not a fan of '-ana' or '-anna' names as I find them too frilly. If I have to pick one: Susannah, nickname Sana. Sometimes sentences don't end the way you think they salad.
Delphi_Blue mentioned Sana too. It's really simple yet pretty. It's new to me, but I think I really like it. And as a nickname for Susannah is awesome, since I already love Susannah.