Yeah it can be a tough choice Eric. I went through the same conundrum recently. I researched all the options extensively and found that of the two versions the ver II 14-140 was not only smaller but optically a little better than its older brother and I was close to getting it, super versatile focal coverage was the real hook. But in the end I opted for the 12-35/2.8....simply because it also doubled as no compromise 'stills' lens too. Like yourself stills photography is my main thing, probably 95% of what I do is stills, so while the 12-35 gives up some in the versatility department to something like the the 14-140 in terms of focal length coverage it more than makes up for it in other ways. I can be on a family fishing trip doing video and with full confidence switch between video and stills without changing lens in the knowledge that the one lens is a superb performer for both tasks....also being f2.8 it will allows me to shoot both stills and video in lower light and afford me the opportunity to get creative with shallow DOF stuff with both as well.
Not to say that there is anything wrong with the 14-140 as a stills lens, it's just that I concluded the 12-35 was more suited to my needs and was less of a compromise being a super stills/video lens despite not covering the same focal range as the 14-140. Like yourself, the bulk of my video work (and stills stuff) is on the wider end.....on the very rare occasion I want to shoot some video at long focal lengths, I bought the very cheap, very small yet surprisingly excellent 45-150HD. Barely takes up any space tucked away neatly in the bottom of my kit back.
Good luck mate.
