I have the M80 and just split a 4 pack of the M-880. If you want more cameras check out this website they have them for $120 or even cheaper the more you buy.
Moultrie M-880 Game Spy Low-Glow Infrared Digital Mini Trail Cameras (8 MP) (4 Pack) : 4 x MCG-M880 : VMInnovations.com
I found that putting my M80 anywhere from knee to chest height has worked best when having the camera level, but I think it is best to try and place it at the height of the bottom of the torso of the animal you are trying to photograph. Tried hanging the camera once at about 6ft high and the angle was perfect with just the weight distribution but ended up moving enough in the wind to trigger the camera too often.
My M-880s appear to behave better than the M80 as far as trigger speed and have a better night time image. When I was testing them out they even triggered with movement on the tv screen way up in the upper left hand corner of the image. Was expecting just pictures of our 2 dogs walking around the house not different frames of the news. It should be interesting how often they trigger to wind. Right now they are looking for Coues whitetail and have not checked them yet.
You made a smart decision buying the Moultrie and not the Wildgame Innovations. A very good friend had a couple Wildgame Innovation cameras break after only one year. He has 2 old Moultrie cameras that he cannot seem to wear out and uses the newer models like the M880 as well. My dad had a Moultrie I40 for 4 or 5 years before someone stole it.