You need them both. The 9-13 is a little high on the bench and the 6-9 needs a manicured shooting position to shoot prone. Get the swivel model with notches and you may as well pick up pod-locks while you are at it. If you happen to shoot prone in snow on stubble fields then the 9-13 isn't high enough a lot of the time and you are left with using a high at the lowest setting and putting up with the added wobble. If you have kids that are old enough to go out with you, but too young to provide their own equipment then you may want to grab a cart when you enter the store. To get started though, buy a 9-13 LM Swivel with pod-lock and a rear bag.