ICs with great natural sounding highs?

Most interconnects cannot do what you are looking to achieve. They either accentuate high frequency information (like your current cables) and sound overly bright, or they absorb too much information to eliminate the brightness, but sacrifice real punch in the process. You need to look for interconnects that have very low capacitance along with a host of other mechanical properties and quality materials that will maximize the accuracy. Silver can do this, but it needs to be properly shielded and mechanically damped.

I second the recommendation for Ridge Street Poiema ic's.

XLO Reference/Signature
Audioquest Cheetah

Currently, my interconnect of choice is the Ridge Street Poiema 3, which I've owned simultaneously with the Cardas Golden Reference. Depending on the mix of components at any given time, I could live with either, however, the Poiema 3's more revealing top end does add a welcome measure to my musical enjoyment. To my ears, it also sounds somewhat more neutral vs. the Cardas, however, I can easily understand why some others might appreciate and prefer the Cardas. It is a very, very fine interconnect. I also owned the Synergistic Tesla Accelerator. Despite both considerable burn in on my Hagerman Pro Frykleaner and listening in my system, I did not find is as satisfying as the Cardas or Poiema. But, again, personal reactions and tastes will vary.

I've been using Kimber Selects(KS-1130), and found them to be VERY transparent. They will allow whatever your source is capable of to pass without hinderance. Some look at interconnects as a tone control. The interconnect SHOULD not affect the signal at all. At least; That would be the ideal. If your reproduction is not accurate with these cables: The fault is elsewhere in your system.