I have a Schneider 360mm/6.8 Symmar-S...absolutely BEAUTIFUL lens, but heavy. The front element is the size of a small dinner plate!
However, since you'll be working primarily from a car, weight isn't an issue for you. You can contact print on any standard enlarging paper--preferably with an enlarger as the light source, but not necessary--but my absolute favorites for contact printing are Lodima and Adox Lupex. The Lupex reveals quite a bit more contrast than Lodima, but has a quite nice warm tone overall that I like a lot. And, since fotoimpex is closer to you than Michael A. Smith, it should be easier to obtain.
