better mid's?

I'm buying an oppo 980 so I thought I'd get some new cables too. My system consists of an Aragon 2004 mkII, yamaha rx-v 659, and klipsch kg 3.5's, and cabling from heartland(speaker and ic's). I was wanting to keep it in the $50-100 range. If I could improve one thing right now it would be the mids and possibly highs. The Aragon pumps the bass pretty good, just needs a little more control. I listen to my music loud when I get a chance to do so, I think some more power from the amp would help in all respects since I've moved into a larger room. I was looking at some audioquest copperheads, but I found a post saying the highs were not that great. So is there a cable that would give me better mids/highs at this price range/ equipment level?