You don't mention the height of the ceiling, but if it's a standard 8-10 feet, I can't see why your PSBs wouldn't perform well in that room (provided you've got adequate power). Stratus Golds aren't exactly small (sonically speaking) speakers. Partitions shouldn't be necessary.
I agree that the short wall would be the way to go if you can make it work. Even still, the long wall should work pretty well.
I used to have my system setup in a room that was 17X40 with 14' cathedral ceilings (the builder called it a "Great Room"). Aesthetics (WAF) prevented me from placing the speakers on the short wall. Even on the long wall, I was able to move the speakers about 3 1/2 feet into the room and it sounded terrific. The only thing that I had to do was add a subwoofer to help pressurize the room. Otherwise, I thought that it was a great setup. No issues with reflections, standing waves, nodes, etc.
I agree that the short wall would be the way to go if you can make it work. Even still, the long wall should work pretty well.
I used to have my system setup in a room that was 17X40 with 14' cathedral ceilings (the builder called it a "Great Room"). Aesthetics (WAF) prevented me from placing the speakers on the short wall. Even on the long wall, I was able to move the speakers about 3 1/2 feet into the room and it sounded terrific. The only thing that I had to do was add a subwoofer to help pressurize the room. Otherwise, I thought that it was a great setup. No issues with reflections, standing waves, nodes, etc.