Which genres of photography are you in? Landscape, portrait, reportage, food, stills, animals, family ... ? I think that's what would narrow down the possibilities considerably. I wouldn't call 23 mm "the wide end" in the Fuji X system, it's really more of a standard focal length (a 35 in the full frame world). Personally, if I could only have two lenses, I'd go with the 35 f1.4 and the 18 f.2, but that's more because of their special rendering (almost film-like, as many would argue). That would be about the equivalent of the 50 mm and the 28 mm in the full frame world, my standard kit back in film days ... For sharpness, versatility and still acceptable low light capabilities I'd chose the 16-50 and the 50-140 (+1.4 converter). But that would be huge and heavy kit ...