TGR is probably the best resource when it comes to info on bindings inserts, there are a lot of folks over there who have used them and put in their 2 cents.
As far as skins, look into G3's. Black Diamonds aren't bad, but G3's seem to last longer, hook on and hold on more skis better, and often have better grip and glide on the uphill. They are also lighter than BD's. To determine size, you should ideally go with something that is as wide, or wider, than the widest point on your ski so that you can trim them down to fit the ski. You can usually downsize a little bit, but beware because the less skin you have and the more base shows, the less grip you will have.