Best Amp + PreAmp for Esoteric X-03

Wouldn't the pairing depend more on your loudspeakers than on your source?

Regards,

My speaker is ProAc Studio 140

As I use UX-3 SE I´d highly recommend looking at Ayre or Nagra gear as synergy is very good. Depending on your personal taste you can fine tune its sound by using either Shunyata, Electraglide or Virtual Dynamics power cords.
My speakers are Ayon Falcon S latest modell, modded Ayre K-5xe + V-5xe as well as Nagra PL-L. Former cdp were DV-50 S (modded) and Audio Aero Capitole MK II SE.

I have X-03 connecting with Mcintosh C2200 preamp and Mcintosh MC501 and B&W802D. Very lovely + dynamic sound (according to my ears and mind)

The only important synergy occurs between amps and speakers.
A good source will work everywhere, a good pre too imho, so maybe you could try a few amps with your speakers and forget about the source (which i really love).