Yeah, my search ended me up with these two lens, both are appealing to me. 180mm lens are a bit tight for my budget, so I considered 90mm or 105mm lens good compromise. Some websites mentioned this focal length lens can also do portrait shots.
For myself, i am using the Sigma 105mm (1:1), if i want larger magnification i would add on extension tube. Yes it's true macro lens between this focal length (90mm-105mm) can double up as a great portrait lens.