Agree fully with drsurf.
Yes, the Peak4 in 3 and 4 and 5 m2 is amazing in waves and for overall flatwater fun too.
I have had the 8 and 11 also, the 11 not my cup of tea as I got other (expensive) kites for this, marginal winds.
But the 8 was dissapointing at first try, as I expected a 5 m2 just more power.
Which it is not.
But it has grown on me, so used extremely often, my goto kite for all foiling, when wind below 12 knots.
Fast to rig, fast to pack, turns okay and a lot faster than the double skin high aspect kites, and it drifts like nothing else, besides almost impossible to get down in the water.
Downside is you have less peak power, as its forward flying speed is lower, so for marginal winds it is not the kite.
But as this thread was about 8-13 knots, and not marginal wind, it could fit.
The double skin foil kites cost twice as much, some of them more.