The faster the ram the more FPS you will get! Although you will be using a discrete GPU in crossfire mode, the APU still stores the game data in the system ram for the alternate frame rendering on the IGP side. If I was you I would cut the memory down to 8GB and increase the speed.
Check this link out, it will show you the difference between each memory speed. Also bare in mind, the more FPS you have, the less chance of micro stuttering!
http://hexus.net/tech/reviews/cpu/46073-amd-a10-5800k-trinity-needs-faster-ram/?page=3
Here
http://www.newegg.com/Product/Product.aspx?Item=N82E16820104315 these will be fine for you. If you must have 16GB just double up, still works out cheaper. Note, you will never use more than 8GB. Fore desktop use, 8GB is more than fine. Save your money and you can put it towards other things.
One more thing, your PSU is overkill!
Hope this helps.