It depends on how much FOC you want.To get maximum FOC AND try to keep overall weight down,you need the lightest shaft in the proper stiffness you can find.I don't have experience with the Grizzly shafts but even the Momentums aren't light and they are extremely expensive.
I draw 29" and shoot bows 53-55# at that draw length.With a black,.340 Gold Tip cut to 30",and app. 400 grains up front(point,adapter,insert and aluminum footing)I get a 709 gr arrow that is 27% FOC,is tough as can be and costs 1/3 the price of the Momentums.
Another setup uses Victory V Force,HV .350's.These are much lighter @ 6.4 GPI.30" shaft,app. 425 gr up front,makes a 655 gr arrow that is 32% FOC.This arrow out-penetrates the heavier,27% Gold Tip but they aren't as durable.No issues on game so far but I won't use them for stump shooting.
It looks like the momentums with 300 gr points would yield you about 25% FOC and about 730 grs overall.If you think they aren't quite stiff enough,add thickness to your side plate.