I use almost exclusively my 50mm and my 24-70mm for most portrait shots. Those would be the lenses on the top of my list. I own the 17-50mm from Tamron and it does as good as the bigger canon lens. I used that for many years and it works great. Unless you need the IS of the canon version, I would suggest going that route instead. Yes the AF is noisy, but unless your tracking college athletes running, I think it will be perfectly fine. I have 3 little ones and it does great catching their movements. The 50mm some say have issues with the focus breaking, but if you are careful with your equipment and mind what you do with it, you should be fine. I suggest getting the hood to protect the lens as it does expand with focusing. I have never taken the hood off that lens. I would also say that the 70-200 f/4 might not be a bad lens to get if your looking at increasing the length of your lenses. Just my thoughts.