Bookshelf/Small Speakers

according to your components, I strongly recommend B&W DM604 monitors. It's truly classic design and champion for asking price.

Define "Best speakers" please. Budget would help. Room size would help. Best speakers -to a degree- don’t matter, what matters is what your favorite sound signature is. Super fancy speakers in an acoustically challenged room is a waste of money as well imho.

Don’t overlook the Aerial 5T. It is similar in design to the Salk that Hilde recommended. 
These are great sounding bookshelf’s but are power hungry. If you’re going to use your Carver you should be in good shape. Not sure what your tube amp may be, but you can bi-amp the 5T too. 
I have mine hooked up to a MA 7900 (ss 200 wpc) and they sound fantastic for a little speaker. A little light in the bass but that’s the reality of a small driver.
While the speakers are well made, the stock jumpers really hold them back. I replaced them with some WW Oasis bi-wires ($90) and could hear an immediate improvement. Money well spent. 
Here’s a little rah-rah infomercial:
https://www.bing.com/videos/search?view=detail&mid=D5210292D83AF9C0A8DCD5210292D83AF9C0A8DC&...

Good luck with your move to downsize. The upside to downsize is there’s freedom in simplicity. 

Hello pikes.  Be sure to check out the Golden Ear BRX, and the similar sized speakers from Legacy and Ocean Wave..

Harbeth p3esr comes to mind, so do the Spendor A1's, or if on the cheap, the wharfedale diamond 225’s or the dentons.....