Perhaps you should do some material research on the wire/jacket combinations. I think you will find that metal elements conductivity do not really rank by the base cost of the metal. As you have already found, pure metal never does as well as combinations, the same is true as for the jacket. What is true for all combinations is that the shorter the cable the better. Excluding the actual materials cost (metal and jacket), production cost set up usually start at about $15K for a single run. So, you are looking at a rather costly undertaken. There are many companies that could do the job, some of which can do military spec fulfillment.
looking for exotic affordable wire suppliers
I've been playing around with various wire lately, building my own interconnects and power cords, and I'm quite satisfied with the results. I've sold many higher end cables over the last few years and I can honestly say that I'm not missing them (well, maybe the 6Sons Audio Golden Eagle pc). I have a nice stash of Oyaide and IeGO AC plugs as well as some some excellent rhodium over silver RCA plugs (can't recall the manufacturer--out of business) but I would like to find some alternative wire options. Everyone has copper or silver or gold +/- variations but I'd like to find some palladium or rhodium (plated) wire, perhaps even platinum if prices aren't too crazy (I think the BMI Shark used platinum wires and that was a vivid though bass shy cable). Does anyone know a supplier for such wire? The only ones I've found are pure solid core wire and these are way too expensive. Thanks for your advice in advance.