What is the biggest sail/fin for a kombat 105?

[silent]

Hello

I own a Kombat 105 (2005), weight 75kg and have advanced level. I would like to know wich is the bigger sail I can use and what fin for this sail (considering tha it uses US fin box). I now use a Gun Target 6.3 with a 29cm fin, but some days other people goes planing with 7.5 or 8.5 (11-14 knots) and I want to know if I can have such possibility with this board before buying a bigger sail and fin.

Thank you very much.