I have the 336A, which is similar to the 336W. They are the cheapest models and meant for big box stores and Wal-Mart. The 336C and 1894s/1895s have nicer wood, and if you get a stainless steel Marlin those are downright beautiful as is. I'm very happy with this though after working on it.
If you do want a custom stock, I found this site where you can order unfinished ones finish it however you like, even make it into a cowboy action model.