At your size, an 18 DIN would most definitely be overkill. As a level III+ skier, your recommended DIN is 8, so the 14 DIN P14/FKS140 will more than easily accomodate your needs. To be honest, unless your already running your DINs higher than rec. at III+ or you think your going to be running them higher in the future, a 12 DIN would suit you just fine.
See the descriptors from the answers to what binding thread below:
-18 + Din bindings: I would only recommend an 18+ din binding for people who are skiing very aggressively and are reasonably heavy. I would normally only recommend something like this for big mtn skiers where you only want your skis to come off in pretty gnarly bails.
-14/15 Din Bindings: I would recommend a 14/15 din binding generally only for people who are 175lbs+ as well as being a pretty aggressive skier. Basically, if you’re not rating yourself as a level III skier and doing big jumps, cliff hucks, and skiing fast ect, you don’t need it and your better off saving your money.
-12 Din Bindings: I would usually recommend a 12 din binding for people between 145lbs and 170/175lbs or so depending on ability. For most people on here, a 12 din binding would be perfect. If you’re a more cautious skier and don’t go fast, take impact ect you should really go down to a 10 din or below binder. Likewise if your aggressive skier you can go up, but be realistic. Don’t get an 18 din binding because if makes you look cool. You won’t be thinking its cool when you’re getting knee surgery and can’t ski half the winter.