Wide angle lenses do not necessarily distort people just because they are wide lenses. Your distance from the subject, and where you place him or her within the frame do. So, will a wide lens distort a head shot? Of course. But that is because to get a head shot with a wide lens, you need to get very close and will probably use the edges of the frame in at least some shots. "Portrait" does not just mean "head shot." It simply means that it is a photo about a person, probably with the person in the frame. This means that wide lenses are not as a rule bad for portraiture. My favorite portrait pictures are generally taken with normal to moderately wide lenses. They are not generally head shots.
I had a Soligor 28/2.8 and it worked fine, not as great as my nikkor 35/2-O, but still it was good. The only bad thing about is the MFD of 18 inches if I remember correctly.