The Fiio, and any other normal 3.5mm cable should work perfectly. The connection point is absolutely flat with no indentation.
Personally, I would have a hard time justifying a $35 cable for a $60 headphone, and I think the original cable is fine. It is quite long at about 3 meters, and I wanted a shorter cable with an L-Shape connector at one end, so I spent $7 for a Honeywell A3 on Amazon, and it is 5 star rated, is well constructed, looks nice, and works great.
Edited by Ggroch - 4/13/15 at 10:26am