Careful there...Angus is steering you a little wrong. I guide ski touring about 80 days a season, and consistently one of the biggest problems people have is NOT having skins trimmed to fit their skis. You will suffer. If you are the 3rd person through on a skin track or greater you WILL slip. Get the 110s or 120s and trim them to fit with just one extra edge width of base exposed. You don't need more than that.

If you're hiking on solid heavy snow, then by all means get the narrow skins and avoid the hassle of cutting. If you're hiking in powder though, you'll need all the grip you can get and should purchase skins slightly narrower than your widest point, then trim them down. It all depends on where you're touring.