DingoSeanBlack Diamond's ultralight mix skins are really light, but the skin tip is annoying.
For wider skis like yours, I say go with a G3 Momix. It will be light, and easy to attach. Also, G3 has a tail attachment that would work better for your skis, so horray.
From what I've read mohair is better for lighter snowpack and nylon is better for heavier wetter snowpack.
I primarily ski Tahoe, does this have any bearing on you recommendation for the mix skins?
Also I'm good buying 120s and trimming out a bit of waist on each side right?
Would it ever be acceptable to buy 108s or 110s and have a few mm of exposed base bear the tips and tails?
I'm not a very large individual 5'7, 140lbs if this makes any difference in how much grip I'll need to move myself uphill.