... Anyone have any idea who the chip provider is for kNC?
I gather they do the chips themselves
No, it is either TSMC or Global foundries. They are the two companies who have the capability to do this. KNCminer did not want to specify which one of those two that they are using for commercial reasons.
There are at least a half dozen companies with 28nm processes. Further, Intel, IBM, and Fujitsu have even more mature 28nm processes than TSMC and Global Foundaries, for what its worth.
Personally, as someone whom has worked in/with the IC fab industry for years, I can say it is a bit ambitious to go straight from FPGA to production ASIC runs. While FPGAs provide ASIC like functionality, the underpinnings and validation of designs are very different beasts. Additionally, mask rework usually costs more than doing an MPW. However, this means you have to wait for the next scheduled MPW run which usually means 3 month lead times.