Hello all

I am building a s&g. it is 15ft3"1/2in long over all and
14ft3"1/2in at the waterline. I want it to be a swede form.the max bottom beam is going to be 24-25 inches wide the max top beam will be 26-28 inches wide.the deadrise will be 2 inches I figure the placement of my seat will be around 9ft.Does anyone know how to figure the center of balance (or where to place the seat is my main question) for a swede style kayak.it is going top be a sit on top (I hope)any one out there ever buit one?I weigh 230. I want high initial stability (used for fishing) can anyone help out ,advise or forsee any problems, thanks for any input.