Advise on book shelf speakers less then $750


I am looking for advice to help me upgrade my existing Linaeum LFX speakers monitors.  I am looking for used speakers with a price around $750 or less.  That have open, detailed with very good imaging and that are small monitors.  The living/dining room I have the speakers in is approximately 13 feet wide by 34 feet deep with 8 foot ceiling.  I normally listen to music at a low volume of around 50 to 65 dBs measured at my couch 8 feet from the speakers.  I mainly listen to jazz, blues, and some rock.  The system consist of a Threshold400a amp, a Threshold SL-10 preamp, Macintosh 7082 am/fm tuner, and a first  generation Sota turntable.  Before you start and say that I need to upgrade my components, have no interest in upgrading them.  And secondly by budget number is fixed and can not go up.  Because of WAF the speakers need to be book shelf size.  What I really want are LS3/5a made by Harbeth but they all seem to be above my budget.  Any thoughts?  
waterford
Elac Debut 6.2 @$250.00 after a price reduction since they have been on the scene a few years now plus the Adante came out. Then there is Elac UniFi UB5 ($500). The B 6.2 i can vouch for and actually own. For 250.00 you get a very decent sounding speaker. The Uni Fi UB 5 i have not heard but they have really great reviews. Somehow i think they would be satisfying especially if you have  100+watt amp... Not a big risk if in my opinion.   
The Uni Fi is excellent, but I’m not sure it is so excellent at 50-65db. That is whisper quiet. 
The Uni Fi is excellent, but I’m not sure it is so excellent at 50-65db. That is whisper quiet. 
I’d second the Wharfedale Denton 80th Anniversary recommendation. I had a pair for just under two months and listened to them about six hours each day. They had opened up very well and were sounding pretty great with jazz and acoustic music. Not amazing for rock, but pretty good if a bit shouty in the midrange for classic rock. But, at your listening volume even rock should sound pretty damn good through these. 
I came across a very nice deal on a pair of Harbeth Super HL5’s or I’d be listening to them right now. Music Direct....60 day approval period. Heck, ask for the pair Carter DeVries  returned! They’re already broken-in! ;-)
Found B&W 685 S2's for $400 not long ago but one can find new ones for $700 and to my ears are transparent w/good imaging and handle rock, jazz and guitars well also have adequate bass. They seem to sound good with whatever you hook them up with and are fairly tolerant of placement since they are front ported. They are 8 ohms w/87 db's and amp recomendations are 25-120 watts. Also very clear for their price range. Also good vocals.