Weight of arrows is a matter of taste i think. I f you are going to hunt a heavier arrow will make the bow more quiet and give better penetration...
But with such heavy bow i dont think penetration will be a problem.
Personally i prefer heavier arrows,my bows range from 52 to 65# and my arrows weigh in at 550-610gn (35-39g)
Heavy arrows reduce handshock,make the bow more silent and i really like the "thunk" they make when they hit
/Mikael