You failed to state how you plan to print such things, color or b&w, from darkroom or otherwise? Lenses
can make a bit of a difference, esp if you plan to enlarge 4x5 this much, but there are much more important issues in the total workflow. I wouldn't worry too much about minor differences in lenses,
unless you are using them with strong tilt or rise movements which require a larger image circle.
It will be a 4x5 portra 160 and imacon x5 scan. I guess I don't need to upgrade...
I'd just go with what you have until you have your total workflow ironed out. Then, if for some reason
there is a shortcoming in your particular lens, you might supplement it with something else. But I don't
see any reason why it wouldn't be adequate. It helps to be on the main road awhile to learn how to
drive before veering off onto the 4WD drive tracks and cowpaths. I did entire one-man shows back when I only owned one view camera lens. I've got better lenses now; but some of those old 30x40's
still look pretty damn good.