Depends on what you like, if you use it more for music then direct radiating are the best and to top that using the same speakers you use in the front in the rear makes it even better. If you are also a fan of music in your movies like me then that is the best way to go, I have Paradigm legends as fronts and rears and they sound amazing in movies such as Ray, Resevoir dogs (anything by QT), Resident Evil, ect. They also sound very good in all other aspects as long as you have them seated behind not at the side of you or your going to be able to pinpoint it exactly. I have mine about 3 ft behind me and I cant' really detect them at most times (they are in my bed room I'm a college student living at home lol) I also have them turned in and set up properly so it even sounds like a phantom center when its suppost to.
The bi-pole/di-pole are great for movies like the Perfect Storm and Twister where the sound is suppost to engulf you in to the action. I think they would be just as good for you if your making a dedicated theatre, it all really just depends on your preference I would go to a hi-fi store and test them out and also the direct radiating speakers. Bring in a few dvd's like Perfect Storm and Ray and also a few cd's or sacd's if you have any and try them out.