I have 5 lenses for my 4x5, but I find I use the 210 Symmar 80% of the time. It's a good, but not great lens. They show up on e-bay regularly. I started off with a brand new Schneider 150mm Xenar. It was not expensive brand new, and it performs very well, except for coverage. It only allows a cm rise or shift. If you do landscapes, it's fine. If you want to twist that Cambo like a pretzel in the studio, no good. If you see life with your eyes wide open, you might try the 90mm Angulon (not SA). Also cheap but has movement to spare and very sharp.
Good luck. Now that you are a 45 afficianado, you will see tons of used lenses jumping out at you on e-bay.