These guys seem to have original USGI stocks in several flavors. They include the metal.
Fulton Armory is another source of new stocks for M14 and M1A. You will need to buy the metal separate.
Keep in mind that original USGI stocks will have the cutout for the selector. A Google of M14 stocks will bring up plenty of hits including some with and some without the metal. Boyds Stocks also makes a good hardwood stock.
Looking at trreeline options there are
HRA
Winchester
SA
Sack,Sons
TRW
What are the differences and which would you select? What basis for your selection?
Which stock are you looking for? Gunparts lists hordes of M-14 stocks and hand guards. Dings and scratches are easily repaired with minimal tools and/or products. Fibreglass isn't hard to make pretty either. https://www.gunpartscorp.com/gun-manufacturer/us-military/rifles-usm/m14/stocks-m14
"...the cutout for the selector..." So did early M1A stocks. Easily "fixed" with Acraglas and some masking tape inside and out.