I'm pretty sure that the 2 channel amp would improve your tunes, but why not an Ayre power amp instead of a Classe. The two Ayre's together seems to me to be the more logical choice. Possibly you can audition both.
What do you expect to gain with the 2200?
Do you plan to to run 1 side of 200 watts to each speaker?
Isn't that what you are doing now?
If this is true, the only benfit is energy not used by the the other 3 channels, however, if you were to bridge the units, then this would dramattically improve your two channel, however the ht sound would not, do to the extra 200 watts going to the mains. you would have to offset the level trims.
I have the 802D bridged with a 5200, it was a big improvemnt, still, these speakers need more power than that to really sing!!
What did you end up doing? I recently went through 3 step upgrade by adding CA-2200, 5200 and SSP-800 to complement my B&W's 803s, 804s and HTM3s. Classe provided much better synergy compared to combo of Krell HTS / Showcase 5 channel amp. I will probably upgrade to diamond series next year.