21:12 Jan 18 

... with your mentioning degrees of intensity. And I guess the greatest inconvenience lies not in the use of modals but the reorganisation of the entire sentence, as you suggested. :)

20:51 Jan 18 

Elena, I think that how to say "чтобы X был не Y, а Z" is a legitimate Ru > En translation question, albeit an elementary one, and that there are plenty of native speakers of English who are also Ru > En translators, who can help the asker in this forum, rather than some other forum. / As for your comment, I have no idea why you think that "should" is restricted to "advice." Should - ought to - must: those are ways of expressing necessity with varying degrees of intensity. Actually, if translating the entire sentence I wouldn't use it, but would say: "wants X to be not Y, but at least Z."

20:19 Jan 18 

Since it does not refer to someone's advice, I wouldn't use "should". I would personally choose "would". Anyway, I think you'd better post this question for native speakers (EN-EN pair).
HTH