Can this camera set the aperture with modern EF lenses, or do I have to get lenses that allow me to set the aperture with a ring on the lens?
And if anyone knows how this camera compares to the EOS Rebel S, I'd appreciate some info.
Since the camera is in the EOS line it is compatible with newer lenses just like new DSLR:s. When I use my EOS-1V (the successor to the EOS-1N) I almost cant even tell the difference from the EOS-1Ds bodies except from a slightly different grip. The only body using EF-lenses that has limited lens controlling capabilities in the line is the EF-M and therefore it lacked the EOS designation.
Regarding the use of an aperture ring, those where abandoned with the FD/FDn system when Canon released the EOS (Electro-Optical System) line and none of the lenses in the new line has a manual aperture ring.
The EOS-1N is a film EOS camera in the professional range and the low-end EOS Rebel S can't really compare to it in any aspects. For example the EOS-1N features 6 frames/second compared to the 1 frame/second of the EOS Rebel S, the build quality is significantly better, the auto focus system is a lot better, the fastest shutter speed is a lot faster and so on. However you can get a hold on the low end canon film cameras for almost nothing, while the EOS-1 line is a lot more expensive (still a steal given what you actually get in my opinion).
It seems like you are thinking about getting either a 1N or Rebel S.
The 1N is a fine camera, however, take the EOS 3 into consideration as well. While having a higher number and therefore being "lower end" it is in some ways even better than the 1N sharing features with the 1V. I own and love both cameras (1N and 3).
I assume your goal is to get an old (and therefore cheap) top of the line Canon film camera. Take a look at this chart that provides a comparison of 1, 1N, 3 and 1V: http://photonotes.org/reviews/1-1n-3-1v/
The EOS 1N can still set the aperture of the EF series lenses in the same way modern dslr EOS bodies do. The 1N still has a lot of on board electronics even though it is a film camera.