As I continue to build my home theatre, I am now looking at rear channel speakers. I have a Paradigm Reference system thus far, though I have been told it makes little difference in the overall sound to have mismatched rear speakers. Are there any placement considerations I would need to take into account in buying dipole rears? I would prefer to place them on a stand, not hang them. My other option would be to get a set of Studio 20s as rears. Please comment.