I see that you plan to suppress the .375 Ruger and have mentioned potentially rebarreling and restocking it. I have a bit of experience with getting a suppressor on my .375 Alaskan, so hopefully this will help.
My Alaskan started life as one of the early, unthreaded versions. I had it threaded 5/8"-24 by my local gunsmith and he reinstalled a factory front sight behind the threads when he was finished. I've been perfectly happy with this setup. I'm not sure exactly what the cost for just the threading and sight would have been, since I also had him glass bed it and install a Pachmayr recoil pad at the same time. Since it's a stainless rifle, no refinishing was needed, just a quick bead blast. Total cost was somewhere between $500 and $600, so cheaper than a new barrel with sights installed for sure. I can just barely see the factory sights over my Rex MG7.
If you can find one of the earlier unthreaded rifles, the above may be an easier option. I've had good luck with my M77's shooting well, so I didn't feel the need for a replacement barrel. As you're probably aware, the factory threading on current .375 Rugers is 5/8"-18 for some reason, so mounting a suppressor will require either a thread adapter, a custom hub mount, or shortening and rethreading the barrel.
As far as stocks, I'm a lefty, so replacement Ruger stocks pretty much don't exist. B&C does offer a lower cost stock for right handed Rugers though. I have a B&C sitting around waiting to finish my custom Remclone in .375 Ruger and it appears to be a very nice stock, especially for the money. I don't think it gives up much to some of the more expensive options except weight, which isn't an entirely bad thing on a .375.