I have a warming filter allways on my 17mm nFD. I have never had any problems with vigineting due to the filter.
However, I have noticed considerable increase in flare when I use the filter. With a very wide angle lens like that, it is often impossible to keep bright areas of sun and sky from hitting the front of the lens. The lens itself is reasonably resistant to flare, but with the filter on it is noticeable even in the viewfinder.
So.. get a good filter like the hoya SMC, BW, or heliopan, and tryu a few frames with and without the filter.
Photo.net also has a good FD forum