Lots of good points made above that you should keep in mind going forward. But just to stick to your original question, my experience is that speaker cables become more important as speaker efficiency drops. My speakers have almost the same sensitivity and impedance as yours (i.e. fairly efficient), and I tend to hear relatively little difference between speaker cables and much more with interconnects. As always with wires, YMMV. FWIW, and best of luck in your search.
