So you pulled the speakers out 5 feet and noticed better "clarity." I assume that means the bass was less boomy and the sound was better balanced overall? What is telling you side reflections are still a problem? How far are the speakers from the side walls and how much are they toed in? These two variables alone could go a long way to fix sidewall reflections if indeed they are causing a problem (see below for more). What areas still don't sound right and what are you still looking to improve? The more detail you give, the better advice you'll get here.
As as far as going to bipolar or omni-directional speakers to deal with room issues, this seems a bit extreme IMHO. First you need to see if that type of sound, which is different from direct radiating speakers, even appeals to you. As others have mentioned my our room does not sound overly problematic as it's very similar to mine and others here, so you should be fine with a little more help and effort.
BTW, to find sidewall first reflection points and treat them, sit in the listening chair and have someone stand with a mirror against the sidewall near the left speaker. Have them face the mirror directly toward the opposite (right) wall and walk directly along the left wall toward you, and when you see the left speaker in the mirror that is your first reflection point of the left speaker that you can mark with painters tape or whatever. Keep moving mirror closer to you from that point and when you see the right speaker that'll be the first reflection point of that speaker on the left wall. Repeat same thing from the right wall. Try temporarily hanging a piece of carpet in those locations to see how it helps (or you can put something like a bookcase there as long as it's high enough). You can follow the same procedure to identify first reflections from the ceiling and floor as well, which are also important areas to identify and potentially treat (a carpet or area rug usually takes care of the floor -- ceiling's a bit tougher aesthetically speaking).
Again, I find long wall vs. short wall is very much a personal preference thing (assuming your room and speakers can work both ways) and you'll probably find yourself finding one or the other more personally satisfying pretty easily between sonics and how close you want to sit to your speakers. FWIW...
