Doug, if your bow is center SHOT (cut 1/8 to 3/16 past center), you will need a bunch of spine; if center CUT, it won't be so bad and you can always build the side out a little to help. High FOC with wood arrows is a challenge, but I have achieved 20%+ with a 28" arrow. High FOC requires a light shaft and heavy point. I prefer Sitka Spruce to POC for this, but POC will work. Paper tuning will tell you what your final spine needs to be, but I figure 10-15 lb above spine for a 160 gr point.
My longbow, cut +1/8 and 54 lb, needed 70 lb spine for a 28" arrow and 250 gr point weight. Arrow is spruce, 640 gr and 21%.
Is all this effort worth it? It is for me; I love the way high FOC shoots and performs on game.