yes you can easily swap stocks. just remove the front band and the mount screw from underneath and off it comes. you can go ABS-black or get a custom wood stock, or even a little better factory. pretty much what ever floats your boat.
i got a real nice stock from rhineland arms for a PSL. I saw their rimfire stocks and plan on upgrading my plastic butler creek one with one of theirs. I believe that you can get one finished from them but I prefer to complete the finish myself. here's the link to their homepage: http://www.troupsystems.com/index.htm
whichever way you go just remember to maintain the overall length requirement as some kits require a longer barrel to maintain the requirement. I believe stock length barrel is 18 1/2" and it is ok but 16" aftermarket may push you under the (I think) 24" OAL minimums
Good luck and enjoy