I used to own the first edition CM5, and their presentation is rather smooth. They benefit from amps that are precise, have controlled and just a bit sharp - that's why they pair well with Rotels. Imo (not that it's bright or anything) you couldn't go wrong with Naim Nait 5si or, if you can find one, a Nait XS2 - they make great partners for B&W (some hate the pairing, but I think it's great). The first XS is known to be rather smooth (I haven't heard it) and pairing it with the already smooth CM5 might make things wrong - I would avoid it. But, the Nait 5si should be enough, it's the natural partner for the CD player and speakers you have (price-wise). IF you want upgradability though, go Nait XS2, since you can later add a Hi-Cap (TeddyPardo or whatever), or get better speakers and stuff like that.
But the others are right. You should try demo Naims. I, for one, love them. But neutral they are not, they just make stuff sound good (to me).