I own the 75 mm lens Fujinon SW, f 5.6--probably my favorite lens, the focal length is wide, but not so wide as to be overly specialized. Similar to a 20mm lens on 35mm.

That said, all those prices are high--you'd be better off passing on them and looking on ebay for a better deal.

You also may want to stay in the 135-200mm range for your first lens, which is closer to "normal" for 4x5.