of the three, I'd buy the 135. This is a fantastic lens that produces spectacular results. But for a
portrait lens, I'd stretch a little and buy the Zeiss 85mm f1.4. Unless you're using that 5DIII as a
point and shoot, the lack of autofocus in a portrait session should be no big deal and the results
will blow you away. It's 2/3 the cost of the Canon 85 1.2 and is a wonderful performer.