Nikkor AI 80-200 f/4.5 lenses are excellent and very cheap (the f/4.0 model is also excellent, but slightly less cheap).
No need to to get a Vivitar in this case, even *if* it were one of the better ones.
Also, there aren't many good M42 mount zooms around (M42 primes is another situation entirely).
I'm not very interested in nikon glass. I have what i need for my f4 already and i never use the fg. i only have interest in it as a backup. What would be a good canon zoom (manual focus) for 400ish tops then?
My fave lightweight street kit is a FG+50/1.8E+100/2.8E--love it.
I recently stated that the Leica 80-200 f/4.0 zoom was generally better than Leica's equivalent non-Apo prime lenses.
(And also far better than the excellent Nikkor 80-200 lenses I reccommended previously in this thread, which makes one wonder what "far better than excellent" really is ;) ).
Other older Leica zoom lenses such as the 70-210 aren't in the same same class as the 80-200 f/4.0: I've heard they are still good (no personal experience), but are essentially Minolta or Sigma designs built to higher specs.
Vivitar sold at least two 75-205/3.8 manual focus lenses. The original two touch model is a very good performer and was a great improvement over the earlier 85-205. I wrote about it in a CameraShopper article some years ago. The later one touch version is also a decent lens. I still don't know whether the matching 2X Vivitar teleconverter is for the two touch lens or the one touch lens. In either case, a 150-410/7.6 is not easy to use. The FG does not have a very good reputation for reliability and can't always be repaired. If you can manage something a little heavier, an FE is a better choice. The N2020 makes a nice manual focus camera with a good feature set and selles for very little. It also has user interchangeable focusing screens. I would not be interested in an FG until the price got down to the $20 range.
Ah oh well i can find a good deal on a 75 to 205 later on in time. Im not in the market for a nikon body though ahha i don't know why everyone thinks i am. I already have an f4s. If anything, i might get a new focusing screen for the fg and use it as a backup or as an expendable camera (risky shots and what not).