Best bookshelf speakers

Hi all,

I'm looking to buy a pair of good bookshelf speakers and since a lot of you here seems to know about speakers much more then me, I figured I'd ask for advice.

Here are the parameters I'm working with / looking for:

- The room is about 1200 cu/ft
- Looking for great performance at low volume
- Rich timbre
- Rich, warm bass
- Natural highs (not metallic-sounding)
- Low frequency range in around 40Hz (preferably 30Hz, but I know, there are hardly any in this range at my price point)
- $500 - $700, new or used

So far I am considering the following options (in no particular order):

- KEF Q350
- Dali Zensor 3
- Canton Chrono 503.2
Wharfedale Diamond 225

So my questions are:

1) From my list of 4, which would be your choice?
2) What other bookshelf speaker would you add to the list that fir my parameters?

Any thoughts are appreciated
You might try to scoop up a pair of Devore Gibbon 3's.
Sorry , but i am telling the true, The good drivers cost money.
$500-700 is nothing
Bryston Mini-T An absolute amazing sounding speaker 
I have been down this road more than once. Opinions from others are all over the place. Their recommendations may be well founded but there is a very important factor to consider..............Some speakers sound fantastic connected to some electronics and horrible when connected to others. If there is any chance for you to audition speakers connected to your, or similar, electronics then do it.I have had speakers that sounded great connected to one system and another...not good.My 2cents.
I agree with @Bache, you are asking for the "sky is the limit" in terms of features but "low ceiling budget." Something has to give.. However, since i am popping off about your situation no one yet has mentioned Elac Debut 6.2 (which i am listening to as i type) or the Elac Uni-Fi-Ub5. I can tell you the Debut are worth every bit of the $250.00 asking price.. I recently connected PS Stellar M700’s amps and the speakers are responding pretty damn well. However, I have a pair of Burchart S400’s coming though so these will be stored or sold in the next few weeks, (maybe).