How do you feel about Llewellyn and Llewella? Does Llewellyn sound masculine enough? It almost sounds like it should be a woman's name in my opinion. I suppose because of the 'ellyn.' Still I really like both names.
Llewella looks unconvincing; Llewellyn is all man! Try watching some Welsh rugby - there's likely to be at least one Llewellyn on the field, huge and sweaty.