amp for sonus faber extrime

pass labs x350?
plinius 250 mk4?
tube amp?
Your choices are kind of limited..I would go with Pass X-350 and recommend (from my own experience) Jeff Rowland 8Ti,Spectral DMA-180 or Goldmund Mimesis 29 (this one was the best of the bunch)
Meridian 557 Amps bridged, sound unbelievable with the Sonus Faber Extremas. I heard this combo at the Stereophile show in 1996. The 557 Amps bridged are a 1000 Watts. Also, check out Mcintosh MC 352