Wouldn't the Polaris, Quicksilver, and Multiple Man just be redo's though?
The 90's team had a very distinct look that hasn't been made yet. I guess you're right about Quicksilver, but that wasn't a very good 'mate to begin with, so I wouldn't complain about an update. I'm never one to complain about redos of characters in distinctly different looks or worthy updates. And 90's X-Factor is my Number 1 want as far as teams go.
I see your point although i always preferred Havok's standard uniform to his 90's x-factor one. Polaris wouldn't be a huge change from her previous one though but minute differences would be there.
A super long shot but I think 2 awesome X-waves would be the Mutant Liberation Front and a 4 Horseman box set.