I'm same weight (75) and use the 135. Much better flex distribution in my mind. As above when getting a little more into the powered move spectrum that extra width really helps.
Look I hold down the same kites as my 85/90kg mates in the same winds and that's with 35s for fins. If it's a big big day the 50s go in but this board really holds a tight as rail...if you look at the design difference with the 2013 you can see why. But it still feels like a Laluz though. My kiting buddy has my old 2013 135 and we regularly swap, very similar feel, except the new ones a tad stiffer and you can ride faster and hold down a much bigger edge.
135 and if you are serious about big air then get a 128 to 130, don't muck about.
Only thing is I don't rate the pads and straps at all...then again I don't rate the pads and straps on most of the boards...their is no excuse for companies that make boards only...make your pads and straps world class and better than the companies that make kites and everything else. It's the least you can do!!!!grrrrrrrr
So I have some naish apex on my laluz, relatively expensive but worth it.