Halcro - we have the same issue here in NZ. The last Aesthetix I saw here was sitting in at a workshop awaiting repair, for which Aesthetix wouldn't provide any circuit diagrams even to the official distributor here. So my advice is if you are spending a reasonable sum of money then talk directly to the manufacturer re servicing. If you cant audition why not buy a less expensive or older generation model second hand, run it off a step down transformer and then, if you like the result, then order a new one with correct voltage etc. The Atmasphere has the advantage of a fully balanced design that would interface well with the Halcro power amps.
Some folk here may be sceptical but my modded Marantz 7 has simply blown away my Jadis, Manley and Klyne System 7 preamps in speed and musical timing, so i'm very wary as you are of laying out huge money on a prayer.
You also need to decide if you want a full function preamp including phono or separates. Do you want MC stage stage, and if so, all tube or transformer or fet based.
Personal favourites that I've heard extensively here are the Air Tight ATC2 linestage preamp/ATM3 mono power amps and the EAR 549 200w mono power amps.
