I love
Alanna from the Lioness books too!! I would totally use this name :D
I guess as an honouring middle name what form of
Allan you chose would have to flow with the first name too. But of the ones you wrote I like
Alanna and
Alaina the most. I know a girl called
Alaina.
There's also Aleena /
Alina Aylen Aylin AlineAileen Ailen
Some of them kind of stretching the
Allan sound a bit!