Ha. I was thinking some of the same thoughts. I was surprised someone else was hoping for a 70mm. :-)
Having to choose from existing lenses, even though I love the 16mm FOV, that lens is too large. The 56mm is not long enough and the 90mm is too long. Sigh...
18mm f/2
35mm f/1.4
90mm f/2
What I really want is:
16mm f/2 WR (wish)
35mm f/1.4 WR (wish) but will take the 35mm f/2 WR
70mm f/2 WR (wish)
That gives me equivalents of 24mm, 50mm, 105mm. Basically what I shot with since the 1970s.