iSonic 3 board quiver for 83kg rider

Dear Starboarders,
Which 2 sizes would you recommend for a speed driven race slalom rider of 85kg?
Sailing on coastal choppy waters for slalom as well as on lakes for speed.
Sail quiver 4.6 - 8.8 sqm camber race sails

Large board
117 too big? 107 of 110?

Small board
80 or 87 or 90?

thanks for advice!
Martin