You can often find nice looking stocks at a decent price on eBay. I found this stock on ebay, almost couldn't see the grain pattern under the oxidized linseed oil finish. One it was stripped of that, and finished in teak oil, the grain really stood out. Even better, the stock had never been on a rifle.
You may have to search for M1A stock, USGI stock, figured birch, figured walnut, USGI birch, USGI walnut.
Here are some from ebay.
http://www.ebay.com/itm/Springfield-USGI-Birchwood-Rifle-Stock-37-/111944763368?hash=item1a106d87e8:g:qjIAAOSwJcZWczPs
http://www.ebay.com/itm/USGI-Stock-for-US-Rifle-30cal-308-7-62-nato-275-/331812552000?hash=item4d4191bd40:g:OKkAAOSwoudW9KRm
http://www.ebay.com/itm/USGI-Stock-for-US-Rifle-30cal-308-7-62-nato-267-/291718755344?hash=item43ebcaf410:g:3zAAAOSwAvJW9KYR
There are quite a few on gunbroker.com also.