BTW, if you want a gooid detachable box magazine for you 700, Badger Ordnance makes an adapter that lets you use AI/AICS magazines in your 700.
I'd not class the M40 as a battle rifle - it's a sniper rifle, a precision tool menat to be used at long range and by an expert. It's not rugged enough for down and dirty 'in the mud' combat, it too heavy and doesn't have the detchable mag the shooter wanted.
If picking a bolt action 'battle rifle' from modern vendors, I'd start with something like an FN PBR XP and add the AICS mag conversion from CDi. There's no appropriate stock, and the heavy barrel add to weight, but the 20 inch version is close to what you'd want.
You really don't need a scout mount if you have detachable magazines, because you probably won't be reloading via clips. A low pwer variable is probably a place to start,m with some sort of backup iron sight. Something like a Trijicon or Leupold 1-4x might be ideal.
You's probably want to add dust cuts to the bolt, and while the Winchester style trigger is simple, I'm not sure how immune to dirt and such it is. The full size claw extrator and fixed ejector blade are both well proven by previous bolt action battle rifles like the Mauser, 1903 Springfield and others.
308 seem the obvious round to pick for such a rifle, as it is commonly available, is size appropriate for the action and has the widest utility in a SHTF rifle.
If you want to go to 7.62x39 or 223, a smaller action seem like a better choice. The CZ-527 is a nice rifle and a good starting point, but the magazine system isn't rugged and is propretary.