A 210 can work for portraits, but with tighter than head and shoulders, some people will want a longer lens. My favorite by far for 4x5 portraits is the Fujinon 250 soft focus, you can do anything with it in terms of sharp to very soft and once you get the hang of it, the results are stunning. I know it seems like the difference between 210 and 250 wouldn't be that much, but to me, there is a meaningful difference, especially when you get closer to the subject. Go ahead and experiment some with the 210 and see what you think, if you are satisfied no need to look further.
Good luck
Doug Webb