Of yours I like
Claire and
Brett. I like
Claire decently (though would prefer
Clare,
Clara, or
Clarity) and
Brett is one of my less thought of favorites. :-) I also like
Brett very much as a female name.
My own picks for twin names would be
Elizabeth Antonia and
Lawrence Douglas. If I could mix and match your twin sets (and change the sex of one), and add middle names, I'd make the combos
Brett Elizabeth and
Leo Jeremiah. Like I said, I'm into
Brett as a female name--kind of snappy, kind of sharp, kind of cool. I think
Leo is sort of the same way, although more clearly defined as a male name. :-)