Lloyd is pretty much on the money as always.
I simplify things a bit. My stock alloy is five parts WW to one part lino. That works well for me with a couple of limitations. I don't shoot really hot plain base magnum pistol loads and I waterquench for GC rifle loads.
Were I casting commercially, I'd offer a basic line and "magnum bullets" at a somewhat higher price. For the great range of loading, a moderately soft alloy is better. I would also suggest that you make sure your bullets are big enough. Undersized bullets cause a lot more problems than alloy.
I've had good results shipping with the "box inside a box" method. The outer container gets a good beating, but if the bullets are packed too tightly to rattle in an inner container, they travel well.