Mono Block tube amp or Stereo Tube amplifier?

I am using Legacy Audio Focus 20/20 speakers, and I have McIntosh C2200 Preamp, McIntosh MC402 amp, McIntosh CD player, and VPI Scout turntable. I am considering Bi-Amping, with tubes driving the Mid/High, and the MC402 driving the woofers. So that is where I am hang up between getting a mono block tube or stereo tube amp. I do realize that I have to use an active crossover in the Bi-amp configuration since the amps are different. Any thoughts on Mono blocks tubes versus stereo tubes amps for this application?

Larry,

I already have a preamp and a solid state amp (McIntosh C2200 and MC402 respectively), and I see the the Onix SP3 is an integrated amp, therefore I would not need it. Can you recommend another Tube amplifier in the Onix price range?