Also interested to hear how you will do.
As agree with jumptheshark, for normal conditions side or sideon, it is useless IMO.
Even the 8 is on the verge to not working.
You said you could not get the 8, but why the 13 and not the 11 then?
Totally in line with Brian H, that the 8 can go down to 8 knots, but not less.
Whereas the 6 can go almost as low, 9 knots, because it is so much faster and can pull you out of the water - but the 6 is an awesome wavekite, the 8 not so much.
Assume you got very different wave conditions, so a big Peak might work for you.
But it does not work for me, have had the 11, but useless and sold it.
Still keep the 8 as it is somewhat in the transition zone, so "nice" to have sometimes, eventhough not good in waves, but easy to pull out when wind drops and you just wanna ride "now".
I can ride in just as low wind as the Peak4 11 m2 with a light 12 m2 LEI kite, and it turns way faster and has more peak power - so better.
Now I have got a superlight 11 m2 doubleskin foil kite instead (turns quite fast), for winds 6/7-8 knots, will see what I prefer in the long run.
Looping and flying fast is the only way to start in each kites low end, with Peak kites below 8 m2.
Above 8 m2 I agree, it makes more sense to sine it, so you get more apparent wind, as they dont accelerate like the small ones.
Peter