1. I personally try to keep my hot spot between 88-92 and the cool end between 80-82
2. that depends on the type of enclosure, if you are using a terrarium you want it to be longer vs tall to create a nice temperature gradient.
That's just me, other people have methods that work for them and their animals. Ultimately I believe that your animals, with the proper amount of hides, will tell you will tell you by where they spend most of their time the temperatures they are most comfortable with.