[oudevolvo]

I priced some copper yesterday. I need 4mm x 70mm x 300mm to cut the shape i need for each strap. the closest i could get was 5mm x 90mm in 4 metre length for $282!
I'll see if i can change the design to make them smaller.

And how about having them lasercut?
In The Netherlands there is a company that has up to 3 mm Copper (CU-DHP-R240) which they can cut. The challenge however is that single piece production is still quite expensive. Two of the same product is only a little more expensive than a single one. So it only helps if you can design in such way that you have multiple of the exact same busbars.

 

[oudevolvo]

Yes copper is more ductile but I can't see any good reason not to use Aluminium , Aluminium is used extensively as power transmission cables and bus bars.

I would definetly use it before stainless steel.

http://electrical-engineering-portal.com/copper-or-aluminium

One thing perhaps to keep in mind is galvanic corrosion
Further read on http://www.anzor.com.au/blog/galvanic-corrosion-keep-those-metals-apart/
My contactors have stainless studs en bolts and therefore I prefer to use copper over aluminium.