Another thank you for all the helpful advice I received on this thread. Here's what happened with my purchase, which took place not very long ago.
I listened to the Dynaudio Xeo 3s and quite liked them but wasn't altogether convinced by the longevity of the current wireless speaker technology. Frankly, I was also put off by the lack of knowledge any of the Dynaudio dealers in New York seemed to have in operating the Xeos. And none of the dealers seemed very enthusiastic about them as a product, perhaps unsurprisingly it seems to me, as they cut out most of the variations they like to go into.
For a while, I was fairly sure I was going to buy a BelCanto C5i and a pair of Totem Rainmakers. I listened to the C5i a couple of times and was impressed, and I also quite liked the Rainmakers. But the salesman at the dealer I went to tried to rush me into buying and I stalled.
While stalling, I had a chance to listen to a pair of Harbeth P3ESRs elsewhere and was amazed by them. I also liked Harbeth's relatively no-nonsense spiel on their website and, after looking into Harbeth's claim that their speakers are easy to work with synergistically, I bought a pair of the P3ESRs in the cherry finish (which is beautiful!).
Then I went and bought the Wyred4Sound mINT separately, another American-made integrated amp with built-in DAC. (I wasn't able to test the speakers and mINT together but I felt reasonaly confident they would match.) The mINT can actually do more than the C5i and is a lot more compact, although it runs hotter. (Online it looks ugly but in person it isn't.) I now have the mINT connected to my computer via a Wyred4Sound USB cable, with all my music stored on an external hard drive, connected via Firewire 800 to the computer. I also use PureMusic, which I find very beneficial and which gave truly excellent customer service when I required assistance and advice. They recommended I buy a cheap tray-loading, AC-powered, external CD drive for ripping my music instead of using my computer's slot-loading CD drive. My speaker cable is a 10 foot pair of DH Labs Silver Sonic T-14.
So that's what happened! If anyone has any advice about the necessity of buying a relatively high-quality Firewire 800 cable (for my external hard drive to computer connection) I would certainly be interested in hearing it, as well as suggestions for candidates in the £100 range.