Why not just use the S&K mount and keep the stock the same. A synthetic stock probably isn't going to help the rifle shoot better, in fact it can diminish the accuracy. The '03s are bedded so that there is roughly 10lbs of upward pressure at the end of the barrel from the stock- they shoot best this way.

If you have a straight stock (which you probably do) the only disadvantage is the lack of a pistol type grip on the stock. You'll need raise the cheek on the stock to get your eye level with the scope- I reccommend a Beartooth Comb Raising kit. Its basicly a stretchy polyurethane sock that comes with cheek pieces of different thicknesses, that you slip over the stock to adjust the comb with no permanent modifications. I have one of these on my swedish sharpshooter rifle because otherwise I would have to turkeyneck to see through the scope.