Hi djlive0123,
Crazily I have the exact set up that you are looking at, I own a pair of MA BX2's with a Marantz PM6003, cables are QED silver anniversary. I have no experience with the CA550 so cant comment but I have been nothing but impressed with the Marantz. I too listen to dance, electro, house and some others like rock so can of course comment on the sound. The speakers themselves are very clear and with the amp produce a surprising amount of bass even when sat on stands. They do need time to settle in as well as the amp as the sound can at times be very clinical but this does settle down. They also need room, give the speakers room to sound their best as in enclosed spaces it restricts the soundstage but with space they will fill a room. As I said I can only comment on the Marantz, I can say that it doesn’t have a dedicated woofer out but then that isn’t an issue as better subs are able to be wired up to the second speaker outs. The remote is nice but has no control for the bass or treble on it which I think I would have liked but the dials are easily accessed on the front of the amp.
I am also looking to buy a DAC which I think will really complete the sound. With this set up I find that if the music is coming from, in my case, a computer then if it is a bad copy of low quality the speakers will pick that up and the sound won’t be pleasant. On the other hand though if you have ripped the CD to say lossless or WAV then the sound is brilliant, perfectly clear at all volumes and the Marantz can certainly push the speakers loud with no distortion. I think I am looking for a slightly warmer sound which the DAC will bring which is why I am looking at the rDAC as it will soften the edges as well as maybe the Rega DAC but that is down to taste and I recommend you trial some DACs when you have decided on your amp to get the sound you are looking for.
I think I have covered a lot here but if you think of anything else I will try to answer from the equipment I have. Important is that if your transport is a computer make sure that the files played are at least Apple lossless but I find WAV provides a noticeably richer sound.