If you just want a camera to use for a one-time project, you almost cant loose with a japanese SLR.
As long as you find one in working condition.
The second question is what lenses do you need for this project?
If you just need a normal, basic wide, or basic zoom lens, again you almost cant go wrong.
Most of the name-brand lenses and even the aftermarket lenses are adequate.
Most of the talk you hear on this board and others comes from hair-splitters who talk about distortion, chromatic aberation, and mtf charts. This means didly for 99% of the shots.
My recomendation: since you allready have some nikon equipment, get a basic nikon like the FE or a Nikkormat. (then you can use the excellent non-ai lenses). or even a Nikon EM or FG with the series E lenses.
Other inexpensive alternatives: Canon AE1 or FT/FTb, Olympus OM1, Spotmatics, pentax ME, Ricoh, Fuji, or Mamiyas.
Like I said, it really depends on finding something that works.
Other alternatives are compact Af models like the Olympus Stylus, pentax iqzoom, minolta freedom, etc.
You can get 2 or 3 for the price of an SLR.