replacing solid state amps with tubes

always in search of nirvana,I am considering replacing couple of my solid state amps with tube amps.My system can be seen on audiogon,but I will provide a very concise decription .I am focusing on the two main speakers out of the the five surround speakers.The german physics Loreley apeakers are bi amped through an electronic x-over at 180 Hz,currently 4 YBA passion 1000 mono amps are driving the speakers.I am looking at replacing the two amps driving the upper frequency ie the DDD section of the speakers keeping the YBA for the bass section.any thought and recommendation of tube amps,they have to be monos of relatively high power the room is large.I listen to primarily classical music.would appreciate your inputs.thank you