huntr1,
As jhm said Richards makes them, I have one on one of my 581s. It is the old classic style which I really like. It has a 13-3/4" length of pull and feels like a centerfire rifle. Richards stocks are semi inletted stocks and require final fitting and sanding before finishing. On my rifle I have the action glassbedded and the barrel free floating. I also had a second action screw added.
I believe you can also get a stock from elk ridge stocks, weings and possibly a couple of others. I have been thinking of getting another Richards stock for my other 581 this winter.