I like both. I think
Eleanor is a little better but
Ellen is more versatile (but also has the potential to sound like a "mom name", while
Eleanor is too classic to have that problem).
Maybe some of these combos will work (I'm not overly fond of most of them):
Ellen DianthaEllen MagdaleneEllen OpalEllen BryonyEllen MarigoldEllen LaurelEllen JoanEllen IvyEllen WinterEllen GwendolenEllen JaneEllen AntoniaEllen RoseEllen CatherinaEllen Padma Ellen TheodoraEllen RosamundEllen Vincente