In a wood shaft, given your draw length and a low stretch string, 70-75# should work. No need to keep the shaft 31 inches behind the point. At your 29-inch draw, could cut them to 30 inches BOP and still have sufficient clearance at the back of the riser. On the other hand, 31 inches BOP will also work. Might be able to drop spine a few pounds if you leave them longer.
Back tapering doesn't reduce the spine much, about 1-3#. Regardless, if you order tapered shafts, they will be put into the spine group after the tapering is done. Tapering also reduces the physical weight about 20-30 grains. But again, the shafts will be grouped for spine and weight after tapering, so just order the spine and weight you want. Tapered shafts recover just a tad quicker than parallel shafts, but most folks feel that parallel shafts shoot just as well.
Tapering doesn't contribute much to higher FOC. The 20-30 grains of reduced weight on the nock end of the arrow increases FOC about 1%. If you in turn, increase the point weight by that amount to maintain the same overall arrow weight, that will increase the FOC another 1%. So tapering with a 145 grain point will give you about 2% more FOC than a parallel shaft with a 125 grain point, all other things being equal.
I recommend you get a test package to start-- 65-70, 70-75, and 75-80.
Good luck.