I've been looking for a kink-free audio only cable for the M-100s (and my XS), but the V-Moda audio only cables are almost 6 feet long. They are light and flexible but they do tend to kink up.
I found a Mediabridge cable on Amazon that fills the bill. The link is
HERE.
I just got a couple of them in today; they cost $8.00, and are available on the Amazon US site. They are very well made, and the step-down connectors fit perfectly into the M-100s and XS, and also into my iPhone with a case on. They are not quite as flexible as the stock cables, but they do not kink at all, and they look great. Secure connection, good sound, no noise.
The 2 foot length is great for when I keep my iPhone/Vamp Verza in an inside jacket pocket. The 4 footer is plenty for carrying the phone and amp in any other pocket.