Neither the Masamoto VG or the Shun Premier steak knives are single beveled.....both are double beveled knives.
I would not recommend a Chef's Choice for sharpening either.....but it will work at 15 degrees.
The Masamoto is asymmetrically ground, hence the different sized bevels you're seeing. I don't believe the Shun steak knives are though.
A couple of stone's ala:http://www.chefknivestogo.com/3pcset.html
Would be far more useful and beneficial to these knives than a Chef's Choice. Learning to sharpen on stone's is relatively easy and a lot of fun....plus, you'll get them far sharper than with the Chef's Choice.
If you don't understand asymmetry of knives, either ask, or ignore it as some people do and never have any issues with it.