If you are buying an LG or other Styrofoam type incubator you will need to buy a good thermometer to use with it. The one they package with the incubator is not very good and will not give you an accurate temp reading. I got one from a pet supply shop, it's for reptile tanks and came with a hygrometer to keep track of humidity as well! Usually the incubator does not come standard with the egg turner so that is one option you can look into...they have them at Tractor Supply too, I'm sure.
I love my LG and have had a lot of fun hatching chicks with it. I just bought a second one so that I can have one as a hatcher, the other as an incubator.