Fuji ( NPL and NPS ) and Kodak ( Portra 100T, 160 NC, 160 VC, and 400 NC )
WHAT you'll shoot determines the best choice.
Talk to the lab, see what 4x5 shooters use there. It really helps to have the lab on your side !
These are all AWESOME films. I mean, astonishing, wonderful films.
I like Portra 160 a lot.
( you can borrow a 35 or 120 and shoot a test to see how the color works for you... what does your lab print on ? There are different contrasts, just like B&W )