I've been using the Moultry 1.3 Megapixles 1.5 software version, this year. I'm more than satisfied with it, especially for the price.
You have to decide, "how much you want to spend first". Another important factor is, how often you'll be attending it. If your gonna have it mounted by a feeder or a trail, etc.
Check this link out, they know more than all of us, put together.