I have the 180/4 for Hasselblad and the 250/5,6 for Rolleiflex SL66. Both are nice lenses. My 250mm is a bit soft. I havenīt done a real side-by-side comparison yet but the slides from the 180mm look sharper. I have seen Kenna shooting the 250mm in his videos though! Often together with an 2x Mutar. You can also use a 1,4 converter to turn the 180mm into a 250mm. However, the 180mm is one of the more expensive lenses and the 1,4 XE is not cheap either. 250mm CF and even CFi lenses are real bargains on the other hand nowadays.
I doubt that there will be a striking difference if you only print 8x8". To save weight, you could even use a 150/4 or the much despised 160mm.
Concerning the wide-angle. I donīt think a 60mm would make sense if you already own the 80mm. Too close in focal length. 50mm would make more sense, maybe even 40mm or Biogon.