I really love Gwendolen, this spelling only. It has an ethereal and poetic feel/vibe to it to me. (But only when spelled Gwendolen! Gwendolyn has an entirely different feel to it.)
These are my favorites from your combinations...
Gwendolen Aster
Gwendolen Capucine
Gwendolen Hesper
Gwendolen Iris
Gwendolen Mathilde
Gwendolen Pearl