Those gear train examples in the o.p. don't look right to me. I'm a gear inch fossil and I'm not about to put every tooth of a custom cassette into a gear inch calculator but: 42 x 13 as a top gear is impractical, even for MTB. That's 80" with a typical MTB wheelset. Is the o.p. MTB or Road? We can't discuss this intelligently until we know what they need. But ... as I understand it, a Rohloff IGH hub has 14sp with exactly 14% steps between each one! Only $1500USD. Maybe?