It's too bad that that since I don't live in Wales (or even among a Welsh community) many Welsh names would be impractical for me to use. However, I just can't get over how magical they are!
From your list, I love:
Eluned,
Bethan,
Robin (as a male name), and
Elin Mair - what a great family set!
I also really like:
CatrinErin GwenllianAriaElin SophiaNerys (I love this one!)
LowriElain (I love this one, too!)
Dafydd (although it's not practical for me)
Dwyfor (really cool)
Ellis