MP,
If it were me, and I am collecting parts and will have one built here soon, it will be 6.5 4S with Vias break. I have a 7 SAUM sitting in the safe and a #3 Bartlein barrel sitting in the corner of my office. I'll likely go Bansner stock as I have others built using the Bansner and I want similar ergos.
Like you say, I'm doing my best to incorporate all the characteristics. I'm certain that GAP built it the way they did for a reason. <grin>