Dude, DONT get running boards. If you are in the same situation as I was when I got my rig without running boards, get some Slee StepSliders or Slee SliderSteps (yes there is a difference). Your wife will LOVE you for it. Also makes the rig much more grandparent friendly and female coworker friendly although I do miss the "panty-shots" I used to get as girls would trapeeze themselves into my rig!!!
The FJ80 was never offerd with running boards in the US market. A domesticly sourced accessory running board kit was offered starting in the 1993 model year. That kit will not work on a 91-92 due to the change in the fender flare size between the 92 and 93 year model. they could be fitted if one also changed out all the flare$. Of course it is a bit of a moot point as the later kit has been discontinuted for quite some time now.