Ray,

Stock fit is critical to achieving that neutral position on the rifle that gives consistent results. The newer you are to precision shooting, the more critical it is. Whatever you do, do something that is adjustable for cheek height and length of pull at a minimum. Better still, the cheek piece should be adjustable left to right. This allows you to get you head more on the centerline of the rifle, reducing the amount of outward torque generated by your cheek weld that must be countered by your shoulder or right hand. All those competing forces add up to a non-neutral hold on the gun, and that leads to variability. If often shows up as a wandering zero.

A detachable box magazine is relatively unimportant for the local comps. I single feed every round anyway.

Find the most adjustable stock you can afford. Bed it yourself if it needs it. It's easy.

I'll vote for the AICS, but I understand it may not be possible due to budget.