The 99 will be a good choice for you,
I am 73kg and mostly use the 88 but i like small boards that's why and on Bonaire the wind is mosly for 5.2 sails so the 88 is the one i like to use the most.
I use the 88 with sail size 5.2 - 4.0
When I use the 99 is when I use sail sizes 5.2 - 6.0..
Taty Frans NB-9