recommendation for speaker wire to soften the highs if possible

Cardas newer cable clear reflection has some of the warmth 
of the Older Golden cross,and some of their top clear .
priced pretty fair also.

I found the older Cardas took the edge off. 

@gunmetalzin I suggest listening for those harsh highs on headphones to see if the problem surfaces there. If that’s the case, your speaker cables are not the cause, and you need to look elsewhere (try a different source) to pinpoint the culprit. FWIW, I run Monster Standard 12AWG speaker cables from the 90’s, and they perform admirably. I also use Monster Standard interconnects, and listen mainly to vinyl, so ymmv. 

I have four possible solutions for you:

#1) Order a tube preamp from Schiit Audio. Their Saga preamp costs $349.00, takes a single 6SN7 tube.  Sounds great. I have one.

#2)  Order a Schiit Audio Bifrost Multibit Dac for $599.00.  This Dac also is available as a Delta-Sigma Dac for $399.00 or $499.00, depending on topology.  Worth a look.

#3) Take a serious look at ordering Signalcable brand cables. They're inexpensive and so good, I replaced ALL of my expensive power cords, interconnects and speaker wire with Signalcable. I used to use Kimber TC speaker wire, etc. Take a look at the Signalcable testimonials. They are awesome for the price paid.

#4) Don't toe-in your Ryan speakers, or if you need to, toe-in your speakers very slightly. Ryan's can get hard/harsh with toe-in issues.

Hope this helps. What's nice about all these products is they perform extremely well for not a lot of money (in the audio world). You can order pieces as you can afford. Check out Schiit Audio.  They make nice headphone amps too.

How sure are you that the irritation you are hearing is from the wire??  If you want rolled off cable, get used Cardas...though I would make sure the problem is there.