Hi,
Just a thought, not necessarily an advice.
Clamping the ss fittings on the cable is delicate stuff, but you don't want that to brake or get loose. The mast is much too important and expensive to have it damaged by using home made rigging.

You should check out these companies and find resellers of their stuff.

"Jakob Inox"
"Carl Stahl"

These companies offer architectural hardware and rigging, and you can order ready made , cut to lenght rigging that is guaranteed to withstand a certain tension. The SS cable is welded to the end fittings so breaking or getting loose is out of the question. You can download their catalogues from their websites in pdf form, and then choose the exact type of fittings you want.

Just a thought. Not sure if it would be cheaper than marine rigging.