Congradulations on your new speakers.
I have several recommendations. Do nothing for at least three or four hundred listening hours. Really get to know the sound of your new speakers / system. The speakers need time to breakin… a couple hundred hours and you need to intimately know what they sound like. Also, speaker placement is critical, and after they are broken in the next step is to carefully get them placed… a couple inches or degrees toe in can really make a difference. Enjoy your purchase.
Once you know the sound, inside and out then start thinking about optimizing. You will have to be the judge of what sounds best. But, I will say, I really love high end Nordost… but not their low end stuff. You may think different. The very best cables and worst I have heard on my system have been Nordost.
But you cannot just buy new cables and expect them to be optimal, unless you have extensive experience. With what you hear on your system, you should try at least three different brands. WireWorld, Transparent, and AudioQuest are the highest selling in the audiophile community… Nordost, Cardas, and DHLabs are brands you should also consider. Given your Mac… I would not think Cardas would be a good match (but that is still a guess… I haven’t heard your system).
I would read up on the cables I mentioned (Stereophile, The Absolute Sound, and HiHi+ reviews, not marketing material)… then borrow… from the lending library from an on-line like The Cable Company and maybe your dealer. You need to not only do some quick A / B comparisons… but if you like a couple pairs… then listen for a few days, then switch… then switch again.
I have spent a couple thousand hours comparing cables (interconnects, speaker cables, and power cords). It is well worth the time. Synergistic cables will really improve the performance of your equipment. Well worth the time and money.
Good luck on your quest.