Bipole or Multiple Direct Radiating Surrounds?

I'm building a fully active HT system, and am planning to use identical speakers all around. They would be bookshelf-size, with response down to about 60 Hz, crossed into a pair of sonosubs around 70 Hz. I have plenty of amplifier channels, so that is not an issue at all. The room will be roughly 14x20, oriented the long way. Ceiling height will vary from about 9' at the center (across the short span) to about 6'4" at the front and back. Currently planning on two permanent rows of seating (with room for more temporary seating, such as pillows on the floor in front).

My question is this: Should I go with multiple identical direct-radiating side surrounds, or with single (or multiple) bipole side surrounds? What about in the back? I can also use direct radiating speakers, but wire them out of phase with each other to create bipole speakers in separate cabinets, effectively.

In commercial theaters, they use multiple identical direct radiating surrounds to create a diffuse effect. Can I, should I, go for the same thing? I find the idea of 9 or 11 identical speakers appealing, and it sure would make building easy.