I want to replace my 95L.
I have a 38L prone that I'll learn to wing on when it's blowing hard.
But for the 13/14 to 17-18 range I'm looking for another board (not aiming at winging at 12 knots,might even skip 13 knots. I prefer to kite foil with a 80cm board or prone surf in light wind).

73Kg, 6&4 meter wings. Riding in 1-4ft waves, choppy water.
I do want the smallest and lightest board, but I do want to be realistic.
Should I go for 60L or 75L?

Thanks!

You may want to consider a custom or finding a board between those two sizes.

I'm around the same weight. I ride a 69L 4'8" x 23" jimmy lewis custom which weighs 10lbs. To me, this is the perfect 12knots and up board. I tried a 55l and it was too small and a 75L at 5' that was too big.

I'm riding HA925 and HA725 for foils and 4.2 and 3.6 Reedin Superwing X. This set up covers me from 12-30 knots.

75kg .. went from 95L to 65L. (Currently my only board). ~60/65L should be what you are looking for.
My board is also 23 wide.. I would not go for anything wider than that.
One thing to consider though is water-depth at your location, as it will sink a bit more (if you try to start/stop close to wherever you get into the water...)
I am using a 4m wing in the above conditions and a 5m when you go kiting ...

The only problem going to 10% below your weight is on the 8knot to 14knot days when you 65L becomes a semi-sinker. You struggle to stand up when heads towards 8knots.

At least with the 75L, it will float you while you noodle around waiting for 10 knot+ gusts.

And I do not really see that much difference between 75L and 65L ..... 2 inches?

Im 95Kgs riding the 75L, my buddies are 75 & 80 kgs riding the 60L. If you're not aiming to get up below 10-11 knots no need for a bigger board than 60L for your weight.