I guess I would start by tlistening to a few to see if you like the sound. You may be able to audition speakercraft at a neighborhood installer show room. Based on a budget of $700, I would recommend only spending $40-$50 on the 4 surrounds leaving $180 to $200 per front left, center and right main speakers. If possible, I would spend even more on your center speakers since the majority of the sound will come from there.
Hope this helps