I agree with NOT using an R700 action if you are going to go "semi-custom". By the time you square up the face, re-cut the threads, true the lugs, add a bolt handle, fluted the bolt, cut an M16 extractor, get an aftermarket recoil lug, Nitride the bolt and action, and install a Picatinny rail...you are over the price of a budget custom action. And it is still an R700 action.
Buy a cheaper custom action like a Kelbly Atlas Tac, Defiance Classic, or Terminius, and you have a better, smoother base to build off of. You will not regret it.
Beware...once you go custom, you will be hard pressed to go back to factory.
I have heard numerous guys that build on a worked over R700 say they wished they would have just gone with a custom action to begin with (myself included x5). I have NEVER heard it the other way around.
I like my hunting rifles in the "mid-weight" category. No lighter than 8.5# w. Optics and suppressor, and up to 10.5# for the bigger cartridges. I have a couple that nudge over that weight, but not by much.