This should be decided school by school, because each school may have a different demographic, and that could quite possibly change the type and quantity of technology used.
That being said, your suggestion at looking at other school districts and finding out what has worked for them is a great idea. Our school recently put in "Elmos," which are mounted digital cameras for projectors which were put into each room.
Most of my teachers started using them, and they saved a lot of time, because they could show the class the pice of paper, and not have to look/get a transparency of the paper. It also gives them more options as far as showing short clips, or powerpoints, or stuff like that.
So review:
1) Teacher workstation in each room, with projector and an "Elmo."
2) Computer labs, with thin or fat clients, depending on your needs.
3) Laptop carts, so individual classes can use a set of laptops if needed.