Bookshelf speakers for a NAD C368 integrated amp


Recently purchased a NAD C368/BluOS integrated amp and looking for bookshelf speakers that are a good match. Current speakers are Celestion SL6si that I have had for ~ 30 years which are acoustic suspension and very low sensitivity. 
Music listening ranges from the likes Mark Knopfler to Nora Jones, etc... I’m 69 and tired enough, so nothing too fatiguing but not too laid back. Any suggestions appreciated but no more then $1200. a pair.

thanks, 
ticman
Thanks Vingard,

heard good old things about Sonus Faber, also checking Wharfedale Reva speakers.
I've heard the C368 on a pair of LS50's and would not recommend it.
The PSB X2T are a perfect match for your amp and yes the new Alphas will also work great as well.

Monitor Audio or Dali might be worth looking into as well at that price point...
Audiojedi,

No room for floor standers at this time. Plenty of suggestions and I will give consideration to monitor audio silver 50’s and Dali Oberon and Sonus faber. 
Thank you for your response.
Thanks to all who responded. 
I decided on a pair of Wharfedale Reva-2’s. They fit my needs as far as room restrictions. Surprisingly decent bass for its size, midrange is sweet,  and the cost, $499 pair. I think they were discontinued or Wharfedale is not going to export to US any longer that’s why the nice discount.  Sonus Faber Venere 1.5 I’m sure are similar but rear ported. Buchardts need room to breathe which unfortunately I don’t have. PSB, Monitor Audio and Polk also Wonderful choices and I would be happy with any of them I am sure.