I would get the Marantz pm 5004 since it should pair good with your cdp. As far the bookshelves vs. floor standers topic concerns, in a 3x3 room bookshelves are simply the most practical. IMO floor standing speakers are better but that entirely depends on the type of speaker. I would buy some B&W bookshelves. B&W makes very enjoyable speakers which anyone could appreciate so no nasty surprises when you take your first listen, still a bit overpriced if you ask me. Personally I like ELAC better, they are more cold sounding, tight bass and a flat frequency response in the mids and highs (harsh to the layman but in fact neutral, ear piercing at high volumes though). If you really want to blow the roof off you could consider the Marantz pm7004 + ELAC FS67.2. These floor standing speakers are very, very good IMO, nice soundstage. Moreover they are more or less indestructible, as ELAC claims: "our speakers don't break". Their manual warns that the speakers could theoretical (they don't know an example) catch on fire when "extremely overloaded".
What headphones do you have btw, what kind of music do you listen to and what are your musical preferences?