I like most of your list.
My very very favourite is Tabitha, it's a fabulous name don't listen to people who say it's catty, the feline connotations are part of what makes it such a lovely name!
Followed by Hester (Esther is lovely too) and Harriet. Eloise is pretty, makes me think of the 80's song by - was it The Damned? Quite like Claudia.
Elizabeth is Ok but a bit ordinary compared to the names above.
Poppy is just far too cutesy and stands out as being quite different to your other ideas.
Tamsin sounds like the name of a character from a Blue Jeans photo story (showing my age....), very 1980's as someone has already said.
From your names I'd go with Tabitha Harriet.
You might also like; Eliza, Esme, Ursula, Anita, Lydia, Anya, Meredith, Verity.