For about 45 bucks you can invest in a Tapco adjustable stock. Some people think it's sacrilege to put one of these on an AK, but I love mine and it made a world of difference in how easy and comfortable the rifle is to shoot. Highly recommended, especially if you have a longer than average length of pull.
The Hogue grip is also very nice as the standard AK grip is rather small. Small investments that result in a much easier to shoot rifle.
http://www.cheaperthandirt.com/product/9-54474
http://www.cheaperthandirt.com/product/2-HO74000
