take your bow and shoot a shaft with no fletching on it,,, hold the bow perfectly verticle and without moving your head to "look" tell us what the back of the shaft does when you shoot it----> .500's will work as will heritage 150's and 90's it just depends on what you want for trajectory and weight.
my 45@28 PSA shoots un-weighted 90's but will also shot 150's with 225grain points..
so if you already have them do that or buy the ones you want and bare shaft one and we can walk you in from there.