Aero kombat 117 and fin

[jijou]

Hello

I'm sorry. My english is pretty bad. I've tried to find information on the aero in the spanish and french forum but not a lot of people know this board.
Normally, monday i'll receve my aero kombat 117. My biggest sail is 6,1 and I wanted to know if in the "small wind" and small waves it's interesting to put this size or this board is done for bigger sails. Also I wanted to know witch fin (28 cm?) I have to put when I use the 6,1.
Last question : my girl friend want to use this board. She has already done windsurf with the starboard starsurfer 140l. Do you think the aero is easy for a beginner.
Thanks

Jerome