We sell a lot of these and recommend just going with a stock pack at first. That way you know if you need more or if just that small amount will do you.
---I chose the duct tape/foam on my factory stock. The quality riser that I wanted just cost too much....and the free mouse pad with tape worked too well. (I'm not a fashion show shooter).
If you don't care about the looks at the range, keep what you've got and save for a McMillan or Manners...look for a used one.