I'm sorry if I'm missing something, but why not just get a SS conversion kit:
A 9/10-speed hub with a conversion kit has loads of dish, a proper single speed hub has little or none. That's we spend our money on them. Neither method gives fixed + disc brake at the same time, so they don't meet the original brief.
A 9/10-speed hub with a conversion kit has loads of dish, a proper single speed hub has little or none. That's we spend our money on them. Neither method gives fixed + disc brake at the same time, so they don't meet the original brief.