About fins

[Fernando Luz]

Hi Roger,
I've read your comments about fins in your last threads, but never the less, I still remain in doubt about this issue... I appreciate very much if you could explaine me a few things about this matter:
I'm changing my old board AHD Inspiro 136 lts. for the new Futura 111.
I have 65 kgs., sail in a lake, winds from 10 to 15 knots.
Sails: NP Solo 6.4 / NS Natural 7.0 / Gaastra GTR 8.0 ( planning to buy the new NS X-Type 7.3).

My questions are:
1. I have a 50 cms North Shore fin that I was using in the old board with the Gaastra 8.0, is it appropriate to use with this new board with less volume ?

2. The 38 fin delivered with the new board, is it for what range of sails ?

3. What sizes of fins, do you think I need in my quiver with this new board ?

4. Finally, what kind and brand do you recommend (Tectonics ?) ?

I hope not to bother you very much, in advance, my many thanks for your time.
Best regards
FERNANDO (Portugal)