Hi Kalibur,
First, regarding my previous post, I should add that I listen to rather low listen levels, i.e. 70-80 dBs. At these levels my E-550 still had at least 20 dBs of headroom before clipping. Whether or not this will be enough for you it will depends on the type of music you are listening. That is, it will most probably not be enough to reproduce the dynamics of large orchestras and big bands music, but it will be plenty for most other stiles (including rock and metal). Of course, I am assuming that you do not attempt to fill a large rooms with monitors and an integrated amp that delivers 30 watt into 8 ohms.
Secondly, the E-560 is very underrated. As the nominal impedance of the C1s is 4 ohms the E-550/E-560 will provide 60 watts which in reality will probably be something like 80 watts (maybe even 90 watts). When I bought my Accuphase combo, the E-550 literally kneeled a Bryston 4Bsst (300 watts into 8 ohms) and a Musical Fidelity A5 (250 Watts into 8 ohms) when driving the B&W 802D speakers.
I have listen only briefly to the new E-460 driving the B&W 805 diamonds and I did not compare it directly with its pure class A siblings. However, the 400 serie Accuphase integrated amps are very powerful (much more powerful the ones in the 500 serie).
As I have wrote in my first post in this thread (not to you though), in order to decide whether or not you need the more powerful A/B design you really need to listen both amps driving the C1s.
Good luck and let us know your findings!
Paul