I thought I would post a picture of my finished mohair stripe sweater for your consideration, just in case anyone is thinking of making it and would like to see a "real world" version.
I made it longer than the pattern specifies - I added two pattern repeats above the side shaping...after I had completed the sweater! It was a pain, but it was worth it. I never would have worn a cropped-length sweater.
The yarn is Peruvian Collection baby cashmere - alpaca/merino/cashmere. The gauge is a bit larger than the Botany, so I made it one size smaller. The stripe is indeed kidsilk haze. I felt like a chump for buying two balls of it against my better judgement, just because the pattern says so. Instead, I'd recommend getting 1 ball (there are other cheaper, similar yarns) and winding off a second ball for use as the second "end".