Looks like I’m late to the party, as usual!
Harris BRM-S with the tension nut replaced by a lever. I own bipods that cost 3x as much and the Harris is a great option for the money.
Nightforce 20MOA rail and rings would be excellent.
Replace the trigger with any of the options mentioned above.
Replace the Hogue stock. Again, great options mentioned above. Personally, I’m not a huge fan of the chassis systems with a separate pistol grip on my bolt guns........nothing wrong with them, just a personal choice. If you want a more traditional stock, look at the Grayboe stocks. Of course, Manners and McMillan make outstanding stocks. These options would need to be glass-bedded.
If you go with a Grayboe/Manners/McMillan, I’d recommend replacing the bottom metal with something that takes DBM’s like the AICS mags. CDI Precision and Hawkins both offer excellent DBM systems.
Another stock option is an HS Precision stock with an aluminum bedding block. You can find ones that folks have taken off their Rem700’s for $200-$250.