Audio research vs audio valve

I have Sonus Faber Lutios and I want to get a tube amp to drive them with right now I'm considering an Audio Research VS115, Audio Valve Challenger 180s, or Audio Valve Avalons. I plan to use a Ayre preapm. Does anyone have any opinions, comments or suggestions on these and this set up or suggestions of other amps/ preamps I should consider? Your help is appreciated, thanks.