This should be an easy choice for you. You've done a very good job matching your components. The Pass and the Ayre both do everything well and are very neutral sounding. Because of that, nothing needs to be fixed. You don't have to spend a lot for great sounding cables, either. My first choice would be Audioquest. You should be able to get a very good deal on a pair of Jaguar or Panther. Those are the 2 former current top copper IC's from AQ. The only difference is that Panther uses Teflon and Jaguar uses PE. I find its not that big a difference. They both sound extremely good. The 2 AQ models that replaced them, Columbia and Colorado, are almost exactly the same. Just small changes were made. I own pairs of all 4 and you really have to nit pick to hear any differences. If you can get a good deal on any one of them, you can't go wrong. Also, they are fully balanced. Not all cables are. Like components, you can use xlr connectors on cables and not have them be internally balanced. AQ uses 3 separate conductors.
Another Cable that may come up is Cardas. Ayre recommends them. They're excellent, as well. I have a pair of Golden Reference. I think thats their best one. The only caution I would mention is that they are stranded. Copper tends to have a roughness or grain in the high frequencies. Only the best solid core copper cables, that I've heard, get around that. I don't know if that will be an issue for you because my speakers may be a little more revealing than the ones you have. My best guess would be that you will probably be able to hear that flaw, as well. I use Ayre myself and know first hand that its very revealing. Pass is too.
The only other thing I can tell you is that I would stay away from anything silver. I have some silver IC's and have never had them work between an amp and preamp. I have no idea why, but I know others who share my opinion on this. Save silver for your source components.
