I love
Iona,
Skye,
Isla,
Moray and
Ailsa.
Love them to pieces. :-)
Sadly, I don't see Kilda working as a fn, at least here in the U.S. maybe in the U.K. where it wouldn't sound so unusual. The problem here in the U.S. is twofold: (1) the "kill" sound and (2) the similarity to
Hilda. I love
Hilda, but it's definitely not a favorite over here.
Cillian is starting to catch on in certain circles, but still not in most places. I fear Kilda wouldn't stand a chance.
It would make a great mn, though. There's no reason not to use it, just not as a fn.