As a new-to-the-market rifle, the American does not have a lot of after market support, yet. I have not seen any replacement stocks for it.
As far as others in that price range, I would recommend the Marlin XS7. It has a handfull of replacement stocks available (Boyd's has some nice looking ones, and I know I have seen them elsewhere, as well), so you may be able to get it looking and feeling the way you want. The X7 line has a pretty decent reputation, as well.
There are others in that price range, of course (Savage Axis, Remington 770, Mossberg ATR...), but to the best of my knowledge, they don't have much after market support, either.