While you can do it the way you're thinking about, you're going to have limited control in many cases. In other words you won't really be able to get the hair light or "rim" light to be where it needs to be. Usually the best solution is to have the hair light on a boom and that way you can place it where it really needs to be for any shot.
Actually Dean Collins had a fairly interesting idea for a hair light in his Tinkertube's book. If you want to look into that, here is the link to the PDF of the book that is on his old site:
See page 19 for his Background and separation panel (you'd only need he separation panel).