I think [name_f]Vivienne[/name_f] and [name_u]Evelyn[/name_u] not only have the best flow with [name_m]Knight[/name_m], but also look right in the full name.
I love [name_f]Jane[/name_f] Ayre so [name_f]Louisa[/name_f] Ayre is the most memorable choice on your list. Second choice would be [name_u]Evelyn[/name_u]. [name_f]Scarlett[/name_f] and [name_f]Margaret[/name_f] are similar to [name_f]Eleanor[/name_f]'s mn.