I am about to design and build a Tadpole trike converted with foot steering and hand pedalling as I have 2 artificial legs.

I am looking for a cost effective source for hubs that would be able to have a 12.7mm (1/2") axle.

I would also like to fit cable disc brakes to the hubs as well.

Looking at wheelchair parts suppliers, boy they know how to charge

I can machine my own on my lathe but it would be a lot simpler to get something already made.

Any Ideas of some sources for these?