For a right-handed Remington 700 long action your choices are almost limitless. You mentioned synthetic, but may I suggest you also consider the Accurate Innovations line. They make both laminated wooden and solid wood stocks that include an aluminum bedding block and Pachmyr decelerator pad. A laminated number would be about as stable as synthetic.
Regarding synthetics, I'd go with fiberglass over plastic. There are less expensive lines, such as Bell and Carlson, and pricier versions like McMillan, H-S Precision, Lone Wolf Stocks, Rimrock, and a host of others. Some you can drop in yourself, others will require a gunsmith.
Plenty of websites to browse. All depends on what you're wanting and how much you want to spend.
