I was on a similar exploration for a preamp with a good phono stage because I'm upgrading my turntable (and it appears everything else) in the near future. I actually got the preamp before getting a new amp, which ended up being a BAT VK-250 w/Batpak, but I had seriously considered (and still am) the JC-1s.
I ended up getting the Aesthetix Janus, which I have to say is simply an amazing preamp for the money. Finding a good preamp to match your gear can be somewhat challenging, and finding one with a phono stage which isn't a total afterthought is even more difficult. The phono stage on the Janus is a seriously good phono stage, which I feel easily bettered the other phono stages I auditioned: the ARC PH 3SEI and the BAT Vk-p5 to name a few. It has load settings to suit most cartridges and a built in demagnetizer function both of which can be accessed with the remote.
I find the sound to be very neutral. I'm new to tubes, and was a little wary that I was going to hear the so-called "tube rush" or that it would sound muddy in the bass and overly romantic in the mids. Man was I wrong. A lot of Aesthetix owners have gotten into tube rolling and have had success with Telefunkens, which I may try when I have the money, but even stock this is a very open, accurate preamplifier with stellar imaging and soundestaging capabilities, and a hell of a good phono stage. Seriously.
I also have an SCD-1 which I find mates very well with the aesthetix. I know there are two other agon members using the line-stage version of the Janus, the Calypso. Perfectionist's system used the Calypso with JC-1s, and from what he's written he loves the combo, and Jadem6 uses the Calypso with his SCD-1 as well.
Of the other preamps you mentioned I think the Ayre sounds interesting and I'm sorry I didn't get a chance to hear it. I haven't heard the Mac, so no help there, but in response to Jafox's post I think the Bat Vk-31SE is a great line-stage preamp, but have heard only mediocre things about the phono section, although it bears looking into. I don't think you _have_ to go tube, because the Ayre is supposed to be great, but I do think that the Aesthetix Janus, which you can pick up for around 4,000 used is a great option. It also looks f-in sweet. If you do end up getting one, let me know how it sounds with the JC-1s.
Good luck,
Matt