To put it this way, the camera body is just a box to store the film. The lens is the one responsible for teh image created.
A so-so body with good lens take pictures better than a good body with so-so lens.
However one thing to take note that the body is the one control some jey feature like metering, AF, flash, max shutter speed and so on.
A key feature on a body to look for is DOF preview, especially useful for macro shot.
Good luck on your search.
P.s. I think FM2 is a good buy if it's not too expensive. $900+ is definately expencive for even a new one.