I would steer away from the Barnard, since it's not 100% Rem700 clone i.e. there are not a lot stock options. Also the action should have decent value as is, just sell it and buy something more suitable?
If you go on with modification, do yourself a favor and ask the smith to machine also a cut for safety. Originally S and SM didn't have that, but now it's an option. Lots more choice on trigger when the cut is done. Dolphin Gun Company used to provide stocks for S/SM but it seems they've downsized and currently no stocks on their website.
I do have few S and one SM fitted to AICS stock with special recoil lug. S doesn't have feed ramp, but it should be straightforward to cut one. Since one of the lugs is at 6 o'clock position when cycling the action, it picks rounds nicely from AICS mag (SM of course).