Questions about surround speaker placement.

[Zman2k2]

So, now that my back has healed somewhat, I'm getting into the design phase of my basement theater room. Coming up with some measurements, I have a room that is 10'8" by 12'. What I'm planning is to have the sofa run parallel with the 12' wall. So the distance between the sofa and the HDTV would end up being around 10'.

My question comes from the placement of surround speakers in the room. When I place the sofa in the room, do I need space behind the sofa, or can I place it directly against the wall? If I go against the wall, would I need to use dipole/bipole speakers, or would regular ones suffice?