Fred,
I tried my 80s 5 feet apart with me 8 feet away. The centre image was excellent but too small...too focused. Also there was no soundstage beyond the speaker boundaries. This last observation has a lot do do with room size and acoustics and I would expect that your set-up, given the room dimensions would also suffer from the same.
I experimented with placement for months and found that the equilateral triangle placement was far superior to all others.
Also, don't worry about your potentially bright room. You'll find that you need a very low amount of power and the reflections will likely give you a tremendous soundstage and "air" to the music.
