Great bookshelf or small towers suggestions

I think you're barking up the right tree...given that you are happy with your electronics, and that you would like these to be the last speakers you ever want to buy (wouldn't that be nice!), I would buy the best speakers you can find and afford that have the sonic signature you like.  Chasing cables is not the way to go, I completely disagree with anyone who sends you cable shopping given your parameters.  And your turntable and CD player are fine.  You don't have a big room, so unless you end up with some low-efficiency speakers I don't see the Marantz being a problem.    It's the speakers...not that there's anything wrong with them, they may be perfectly fine for others, but they don't have the sonic signature you like, so find speakers that do.   With your budget you have so many fantastic options, many of which have already been mentioned.

I actually like your idea of going after some 805D2, or even the 805 Diamond or 805S.  They're easy to find on the secondary market, and if you didn't like them after a few months they'd be a breeze to sell.  I don't know that there's another speaker on the market that's easier to sell, or that holds a larger percentage of original retail value, than the original B&W 805.   You could buy a pair, listen for a year, and if you didn't love them you could resell them for what you paid or very close.  Wilson Benesch Arcs are another option, more transparent and a little less boxy than the 805, but harder to find.   I've been where you are, in a space that size, looking for the sonic signature you're looking for - if you liked the 805D3, I think you should go in that direction and don't be afraid of an older 805.

I was in your position last year and did a lot of listening. I use my Marantz as a pre-amp through a Parasound A52 so I have a little more juice flowing. (After you get your speakers chosen and shake some extra funds loose in the future, you might just add a 5-channel amp to your system.)
Before I talk about my choices, let me say that getting all 5 speakers with the same voicing may have been the single best thing I have done. I had been stereo only, then added a pair of surrounds that, even though the same manufacturer, were voiced differently. Then I added a very nice center, but it was also voiced differently. So I looked for a set of 5 speakers, a 5.0 system.
I set my price target at $3k, but eventually moved up to $4500 for the setup. It seemed to be cost-effective - more than i could afford, but I wanted these to be my last speakers.
I tried Monitors, Paradigms, Totems, Goldenears, Quad, Klipsch, and a few more, bringing several home for a weekend. None of these were what I wanted, which you described pretty well for me. After moving up that last chunk of change, it was a face-off between a Paradigm Gold, the B&W 805D3, and Dynaudio Excites. I ended up with the Excite X34 floorstanders, X14 standmounts and X24 center. 
Four things caused me to make that decision. First, I heard no phase-shift, they were clean and articulate with classical, jazz, and vocals - they sounded like the artists when I heard them in person. Second, the floorstanders are diminutive in size and the WAF was better than a standmount. Third, they have a really great dynamic range - they will rock on without sounding like they are shouting (the others shouted) (I use my Radio Shack level meter to know when it's loud because a good speaker can play louder without sounding bad). Fourth, and what set them apart from the B&W, was their ability to sound musical at low volumes. I didn't have to crank them to some thresh-hold to get them to "speak."
In assessing all this now, three months later (I am happier each passing week), I think I like 2-way speakers better, and first-order crossovers. I know intellectually about phase shift distortion, and each crossover introduces that element, especially if it is more than first order. I am particularly sensitive to tweeters, and the Dyn's neo??? led the B&W diamond??? for clarity and dispersion (imaging).
SO, I'd recommend getting a 5.0 system, and that you listen to the Dynaudio Excite series.

I have the sierra towers (w/ Raal tweeter) from ascend acoustics (http://www.ascendacoustics.com/pages/products/speakers/SRT/srt.html)
I'm very happy with them.

'Enjoy the Music' wrote:  "The midrange on the Towers...is a main event. Inner detail is fantastic...(http://www.enjoythemusic.com/magazine/equipment/0312/sierra_tower_speaker.htm)"
I couldn't agree more.

I demoed the following speakers in my room:
Magnepan Super MMG
ZuAudio Soul
Tekton Lore-S
Sierra Towers (Raal)

The Sierras are (by far) the most accurate (based on my REW room measurements) and more importantly: Sound right through their full range.

I've been very interested in the Sierras.  I just wish I could hear a pair here in NYC.   That said, based on what I've read, if I was going to take a risk on something i haven't heard yet, they'd be at the front of the list.

I don't think I can fit the Sierra Horizon center in my setup though.  Just too big.  Would have to use a sierra 1 or 2.

I'm going to start to hit the stores for demos soon.

There are a few Toem's you should check out.  Great sound-to valuse ratio.  I was also very impressed with the Atohm speakers while I was at the Munich Hi End Show.