The Flare 99 is the same dimension as the 111 but the 111 is much thicker..
The 99 would be a good size..
I weight 73kg and use the 99 flare with sail sizes 5.2 - 6.0 I mean that´s the biggest freestyle I use.. I never tried bigger sail on it but I know for sure that It can handle a 6.4 sail..
Both board are great that´s for sure,
Yes, the 111 you can use also with a 21 or 22 cm fin,
On the 99 you can use fin sizes 18-21 cm..
Taty Frans NB-9