The 125 would be your best bet with what is available, but you would have more coverage with a 140mm skin. Since most of your traction is in the back 3/4 of your ski, you'll probably be able to climb okay with a 125mm. The closer the size is to the tip width, the better the performance.
This is one of the most common questions asked regarding climbing skins. I bet someone asks that every week or so on backcountry.com. Check out some forums or websites to get more opinions on the matter. Chances are, a lot of other people have the same questions. Good luck.