"There are only two requirements a speaker cable should satisfy. The first is that it should be long enough to reach between amplifier and speaker. Then having done that, the only other requirement is, ideally, the colour of the insulation should match that of the surface on which it is lays".
To make it short, cables do some difference, but this is exactly the last component you need to think about in your system.
Let's say that you have a budget of 20.000$ for your audiophile system. I would invest 7.000$ on speakers, 7.000$ on amplification, 5.000$ on source, 800$ on room acoustic treatement, 200$ on cables.