Bookshelf speakers for a NAD C368 integrated amp

Kef LS50. Assuming you have space and stands and not actual bookshelves.
For less money, look at the Klipsch RP600.

Noromance,

thanks. I do have some room restrictions and they would need to be no more then 12 in. from rear wall. The port is in the rear not sure if it matters, but will give a listen.

JM Reynaud Bliss Silver used here.  These are worth looking at for sure.  More efficient, front port and image like crazy.  Good reviews and meet your max budget limit.

https://www.audiogon.com/listings/lis9hbj3-jm-reynaud-bliss-silver-monitors

Why waste money? Get the PSB Alpha 5's and a good TT/cartridge/LPs with the money saved! Only $349! Check out Atkinson's test and review in the October Stereophile. 

Check out the Monitor Audio Silver line.  Good bass extension.  12" from wall will not be ideal but should not be the end of the world with those either.  

FWIW, I am running a NAD 368 BluOS  with Buchardt Audio S300’s in my living room. 
Took them a while to break in but I am enjoying the combo. Not too bright or too laid back, just about right to my 59 year old ears. 
I have them off the front wall by only 12 to 14” and don’t seem to have any problems. At least at the volumes I’m running them at.  You could tame the port a bit with foam if it was a problem. 
Of course YMMV. 
Good luck with your search. 

Thanks for all your input. I will research all suggestions.

I owned the C368 briefly.  Given my experience with this integrated amp (slightly dry; cooler side of neutral), I would suggest a used pair of Sonus Faber monitors.

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.

I second the suggestion of PSB Alpha P5’s. I was very impressed with them.

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.