NHT's floor-standing speakers are designed to be placed close to the front wall. The 3.3's retail for $4,300 but can be found used in your price range. The 2.9's are in your price range. Good luck.
Speakers - rear wall placement
Need speakers that are designed to work within 6 inches of back wall. Looking in price range $3500 new, or will buy used. Have CJ CAV 50 tube integrated though may change if necessary.