I like the idea behind the F3 suggestion, above. Here's an even cheaper Nikon option that will get you shooting some great pictures: the little-loved FG. :D
You can get one for - no kidding - $30. Also, you could pair that with the 24mm f2.8 lens - a hundred bucks will get you a good one - and throw a ten-dollar filter on the front and you're DONE. Less than $150, and you have an AWESOME rig that you can upgrade easily later on! That leaves you $350 left over, which will buy you somewhere around 81 rolls of 36-exposure Tri-X 400, which is a minimum of 2916 exposures. Even I could get a good one with that many frames... :cool:
I am the big ugly hairy friend. Sigh.
Meters can be very easily tested for accuracy at home and a roll of film can guarantee that a shutter is operating normally.
Classic cameras go *slowly* out of adjustment with age, whereas electronic marvels can drop dead suddenly and without warning.
I may have missed it but where are you located? If this is just for a project and you mainly shoot DSLR then you might consider borrowing equipment. For example, if you lived near me I could lend you any number of Minolta bodies with a 28mm, a Nikon F with a 24 or an Olympus OM-1 with a 24mm. Unless you are going to continue on with film, which is a big possibility, after the project ends then either renting or borrowing makes more sense. It would give you the ability to try different makes and models without making a financial commitment until you figured out what you like.
On my shelf, I have a few that would seem to fit the bill, but only one (other than the dSLRs) that has a wide angle lens at the moment: my X700. I have a 28/2.8 hanging around somewhere for it. The camera is a joy to shoot, and I'm learning to love it despite a poor set of test shots I made the mistake of taking to CVS. It is electronic, however, so I'd probably use my K1000 as a non-electronic 3rd world camera. I've used 'em quite a bit my whole life, so I'm familiar with the meter, and it just feels good in the hands.
Or... if you're looking for something newer, within your budget, (though I may get a few crosseyed looks) there's the Nikon FM10. It's made by Cosina, and probably won't take a beating like some of the other cameras mentioned here, but I've made some of my favorite images from my faux Nikon. Add a decent wide angle lens and stir.
The Nikon FM10 and the Yashica FX-3 are like cousins.