Margot, approximately what length will each of the cables be? The Clear Day speaker cables which have been suggested have received much praise here and elsewhere, but their very narrow gauge raises caution flags in my mind if the run length is to be longer than say 8 feet. At least, that is, if the double shotgun version is not used, that being significantly more expensive than the versions which employ fewer conductors.
Steve/Williewonka, I don't doubt that the cables you suggested are excellent, but note that the retail price of all of the components in the system totals a bit more than $5K. The gZero cables strike me as being a bit pricey in that context, aside perhaps for the bottom of the line models.
Also, Margot, a lot of members here have reported excellent results with cables that are at much lower price points than those suggested above, including Signal Cable, Mogami, Canare, Blue Jeans, Vampire Wire, and others. And it's worth noting, also, that the relatively high impedance of your friend's speakers (see Figure 1
here) will tend to reduce sensitivity to speaker cable differences, compared to many other speakers.
Best regards,
-- Al