In the front room of my own house (now empty & for sale) I have a spotlight systen which has 2 rails & 3 lights on each, these were used to light the prints on display, actually non of my own. It was a relatively inexpensive system and worked very well.

My system just fits in place of a normal light fitting in the center of a ceiling and came from a small UK chain of stores but Ikea have quite a good range and are International.