Speaker placement with big screen in the middle

My speakers are placed 20 feet apart with a 61 inch big screen in the middle. Seating is 15 feet away from the front of the screen. Should the main speakers be placed several inches in front of the big screen to avoid imaging problems when listening in 2-channel? I live in a loft...my room is 70 ft long by 22 ft wide and my ceilings are 25 ft high. I wanted to get a projector and roll-up screen but trying to configure it with my room dimensions became way too costly, so I went with the big screen and said to hell with it. I'm happy with the home theater setup and I haven't done any serious listening to 2-channel since I got the big screen. Well, the novelty of surround sound and a big screen is wearing off and I'm looking for a little advice on how to get the two to coexist and get the best out of my 2-channel components.

My 2-channel stuff:
Preamp..............Audio Research LS-10 solid state (no phono input)
Phono Preamp........Carver C-19 Tube preamp (I have it connected to the AR LS-10 and use it for a phono preamp)
Speakers............Infinity Kappa 9 (bi-amped)
Amps.................(pair)Carver Silver 9-t monoblocks (low pass)
Amps.................(pair)Carver Silver 9-t monoblocks (high pass)
Phonograph..........Oracle Delphi Mk-I
Cartridge...........Grado Reference Platinum
CD Player...........Carver SDA/360 5 disc changer
Tuner...............Sansui TU-X1

My home theater stuff:
Surround Processor...Sunfire Theatre Grand II
Rear speakers........Infinity Kappa 7.1
Center speaker.......Infinity Kappa Video Series II
Rear amplifier.......Carver TFM 45
Center amplifier.....Carver TFM 45
Television...........Phillips 61 inch
DVD player...........Samsung M-301

Note:..... I have the Sunfire processor routed thru the AR preamp