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...