i agree with Pat, sinew for insurance purposes alone, will add excessive weight, and a lot of time and maybe expense- unless you already have the sinew.
for sinew to offer its maximum potential, it really needs to be brought under tension, on that long a bow and at that draw length, it wont really be working at all.
Yew , with a good , sound sap wood layer should need no backing for insurance, but if i was inclined to do so, i would use nice thin rawhide- ( goat or sitka blacktail from the PNW
) or even silk.
Like Pat said, sinew works best on quite short bows. 60 and under for sure.
as to design, i really love bend thru the handle bows with flipped tips, both of those design features will allow you to create a much shorter bow.
but if you want to retain the length of the stave, a beautiful ELB, or flat bow would both create a beautiful arc.
In reality, the ELB design is way under engineered for what the yew can handle, yew does shine as nice tight recurves and shorter bows!!
but whatever you do have fun and enjoy the outcome!!