I would do 24-26 to keep speeds high w/heavies and blast down given range work. Accuracy? Likely same/same in a heavier contour you will be using, stiff either way. I'd be leaning on a 700 if you want to use a factory Rem action, if not a Tikka T3. Stock options a plenty in 700, not so much in 7.

Scope subjective, but you want quality glass, high zoom of course. High end Leupold and Nightforce would be good to go.

Many quality barrels, Bartlein, Krieger, Lilja, on and on. A good smith is as/more important. 8 twist would be preferred, no slower than 8.5 ROT.