Ya know what, I changed my mind.

My vote is for about whatever non-SAAMI cartridge is out there, let's go with a 7mm Mashburn, because that's a fire favorite for those looking to be difficult. 28" #5 contour, spiral fluted barrel, threaded right hand metric because I have an off brand suppressor that you need to make work. Purple stock with brown speckle. 12" length of pull, because Take_A_Knee said a short LOP is best for squaring up to a target.

I think that about does it. I'll pre-order five rifles, right now.