I would go with the Winchester 180's then since you know your rifle will shoot them.
You have a Monarch Scope so you can go to the Nikon Spot-On ballistics calculator and
use their data to set up the scope the way you want it. I use it on my Nikon with the BDC and it is very accurate. Another good calculator is JBM. The 180gr Winchester bullet has a BC=.382. Just plug in your elevation, temperature, humidity and 3000fps velocity and what you want your zero range to be, hit calculate and JBM will give you accurate data on your ammunition's ballistic performance for the data you entered.
JBM - Calculations - Trajectory