I'm 6'5" and about 110kg
I gave up on kiteboarding company boards a long time ago. I also just do not like how they ride.
I use hollow carbon fiber Aviso boards.
My lonest is a 6'8". It is a replica of a 70s mini gun surfboard for big wave riding. It is relatively narrow and long with a skinny tail making it really agile
in the waves despite it's length. It is fast as hell and rides really smooth over shop.
I have other sizes too. I have slowly collected 5 of these boards. I even scored an Aviso that has a modified design and build for kitesirfing.
It has straps on rails that allow for really quick adjustment of the straps based on the conditions. I also got my hands on some old Naish footstraps that are huge.
My feet are size 16 with high instep. It is an amazing board.
My all round low wind board is an Aviso Lost Mayhem 6'4". It is relatively wide and has a board concave to it. I use a special hull wax on it that really makes it zip over the water.
The wax does make the board very zippy and it will easily zing out from under my feet when stitching my feet around.
I pretty much ride then all strapless. Strapless is the way to go for heavy riders. Kite companies always put the foot straps way to war back
and have a pathetic range of adjustments.
As you can see here I ride my board very far forward.