Mixed Use Space - Advice for speakers placed close to back wall

Audiophile79, many speakers with do fine close to the wall. Any dynamic speaker system in an enclosure with added sound absorption on any adjacent wall will work. Horn speakers in particular do very well as they are more focused and the adjacent walls do not reflect near as much. Something like the Klipsch Cornwall would be excellent particularly in a larger room like yours. Classic Audio Loudspeakers would be optimal http://classicaudioloudspeakers.com/cgi-bin/index.pl?fs=1&init=1
These are atmasphere's favorite speakers. You want to set things up so you have a symmetrical situation for both channels. You do not want to put one speaker in a corner and the other in the middle of the wall. The frequency response of the speakers will vary so much you will never get an acceptable image without a lot of DSP.

Most speakers without rear ports can do well with their back close to the wall. For what it's worth, Magico does well with respect to this as they're sealed designs—many homes in the Bay Area have limited space available and require speakers to be placed fairly close to the wall.

I agree with mijostyn that the radiation pattern control of a good (low-coloration) horn would facilitate getting good spatial qualities with the speakers up against the wall. Early reflections are arguably the ones most detrimental to spatial qualities, as they have the strongest "playback room signature" cues. Good radiation pattern control in the region where we get most of our localization cues (north of 1 kHz or so) would make sense to me for your situation.

Adequate bass energy to fill such a large room calls for a "brute force approach" to a certain extent, in my opinion. Your room is ballpark five times the volume of a ’typical" room, assuming your ceiling height is the normal eight feet. I don’t know whether your big REL will keep up with your next pair of speakers or not, but two big RELs should.

On the other hand, up-against-the-wall placement offers an opportunity to get away with less air-moving capability in your main speakers than if they were placed well out into the room, but imo the design should be "voiced" with the expectation of what close proximity to the "front" wall will do to the frequency response. Not all speakers work well in the bass region when right smack up against the wall like that.

In addition to mijostyn’s suggestions, you might consider the JBL 4367 (with subs) or the JBL M2 (subs arguably optional). A few years ago a customer asked me for guidance on speakers which would work well up against the wall in a similar-sized room, and he ended up choosing to go with something custom which took into account the factors I mentioned above.

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Vivid works well placed near wall.  They are designed with flexibility in mind and the Kaya line is a GREAT all around speaker for movies and music.  Aesthetically, they are different.  But they are brilliant.  I have Kaya 45s here and they grow on you.  

Magico is a sealed design and I know folks who have them in tighter locations.  They like power to come alive but they may work well for you.  

Those I think are the most interesting options.  I am Vivid dealer.  I am not a Magico dealer.