If you have the choice of those two films/formats then pick 120 Tri-X. The reciprocity problems are much less with Tri-X and with rollfilm you can more easily make multiple variations of exposure, field-of-view and so on. It is also possible to light the foreground with a flash or torch to give a mixed lighting effect, similar to what P-de-J did above around the building.

The tiny dots of the stars are visibly elongated after only a short time - the Earth is rotating at one degree every four minutes after all. Most likely you would be looking for a more dramatic effect of course, so a much longer exposure would be better. The stars are bright, so any long exposure will effectively be over exposure, but that doesn't matter as (with a normal lens) they are far too small on the film to show any surface details anyway. If the ground is completely dark and there is minimal town-glare then choose the exposure based on how long you want your star-trails to appear.

The moon is a sunlit landscape, so will be overexposed very easily if you have it in shot. In general, it might be good to be generous with the exposure and reduce development in order to try to keep the neg more printable, regarding the contrast, especially if you have any ground or horizon detail in the shot.