The Pass X-2.5 and X-1 are excellent matches for the X-250 power amp, I preferred the X-1 over the Sim P-5 and Sonic Frontiers line 2. Cannot help you with the Ayre. For SS preamps the Tom Evans Vibe was a killer preamp and bettered the Joule Electra 150 (a real nice sounding preamp with the X-250), Lamm LL2, BC B-3, and a few others. I prefer a tube preamp with the X-250 to get the mid range to sound more real (I like tubes in my system) unless you get the Vibe.
Hope this helps.