Speaker for nearfield listening?

I agree with Wolf, and would add the Thiel MCS for consideration.

My Shelby+Kroll Nano Monitors and dual Woofer Monitors are crazy good in the near field. For your listening at 6' a single Woofer Monitor would be sufficient. The imaging of the S/K is spooky real.
When the S/K Nano Monitors were first delivered I had them set up on a counter top and couldn't believe what I was hearing. Superior height,depth, and width to the sound stage, with perfect tonal balance. When the stands showed up I put them about 3' off the front wall and 8' apart. From my chair they sounded exquisite, but here's the cool part, when I would get up to turn off the gear (rack in middle of front wall and against it) I would stand about a foot in front of the speaker plane and still enjoy a 3D sound experience! Feels like you can reach over and smack a cymbal.
I first heard the S/K Nano Monitors and Woofer Monitor at a guys house and were about 6' apart and sounded great there too.
Good luck

Depending on your amp I would say try the KEF Q300 bookshelves. With a Jolida JD-502P tube amp with the KEF Q300 speakers I found nearfield listening very enjoyable. When I swapped out the Jolida for a Hafler 9505 solid state amp and the music got really forward but could still be loud and clear from a farther distance.

Second the Harbeth P3ESR. Not such a fan in the past but they have upped their game and are far more dynamic and resolve better. No longer that laid back British sound.

You might audition speakers that have a single driver, like the Audience The One. They resolve beautifully at close distances.

Speakers from Harbeth and Spendor that are designed as nearfield monitors are also a good choice.

Finally, I had a pair of Totem Arros that I listened to from about six feet distance, and their imaging was spectacular. This speaker is known for its ability to create a soundstage in a small environment.

Speakers with coaxial drivers like ones from KEF and Tannoy work well for nearfield listening (I use an older pair of KEF Q10s in my recording studio and they blow away most so-called "pro" monitors) as the driver blending is done before the sound gets to your head.

Getting new speakers may not be your only option. Your amp, preamp and sources play just as important a roll in how your system images. But it all depends on what kind of gear you currently have.

A lot of speakers even very large ones can work successfully in a near field set up if you know what you're doing. You can also look at studio monitors that are designed for near field listening that are easier to place. If your problem is imaging then I suggest that you look at your room and placement. I don't know what's behind your speakers or on your floor nor anything about the acoustical issues in your room. You need to assess all that and play around with both your speaker placement and your listening position. Your listening room is a critical component of your system!

Lipinski L707's You don't really even have to toe them in. Fantastic sounding. I may be moving up to the next size due to moving my system downstairs going from an 18x17x8 to a 34x26x9 room.

Harbeth P3ESR or Spendor 3/5r2 are two I would give a listen to! I have owned the Spendors and now have the Harbeths. The Spendors are a little laid back in comparison to the Harbeths. Both are top notch for close up listening!