You already have an 85mm lens, do you like the focal length and the only problem is that it's MF? If so, the 85/1.8 would be the way to go. The 100/2 would work as well, the two lenses are very close cousins in terms of building and IQ. Personally, I love the 135/2L, but I think it's too long for portraits on APS-C. Likewise, the 100L macro is a great lens, but with the deeper DoF (for the same framing) of APS-C, I think you want the fastest lens possible for portraits, and f/2.8 isn't as good.