Switching from solid state to tubes

Hello all, 

I am looking for advice regarding the purchase of a new (to me, not brand new) amplifier. I currently run a 5.1 home theater system with Sonus Faber Olympica IIs as my mains, Olympica Is as my surround, and an Emotiva center channel and SW. They are now being fed by an Emotiva XPA 5 that receives its signal from an Anthem AVM60 processor. I currently use the system 75% of the time for stereo music and the rest for 5.1 movies. And when it comes to music I do 50/50 records and streaming. 

I recently put together a Bottlehead amp and am really loving the tube sound and would look to bring that into my main system. But here are my questions going forward:
1) Would it be silly to bring in a tube amp to drive the mains and keep the rest of the system through the Emotiva SS?
2) If not, what power output should I be seeking for the stereo amp? (The Emotiva is currently rated @200 watts (8ohm)) 
3) Will the Anthem processor be able to properly match the output of the different amplifiers so the volume is nice and even across all channels? 
4) Do you have any suggestion for an entry level tube amp that matches the Olympicas well? 

Thanks!

-Al