Of course not knowing more about your school or your budget, it’s difficult to give specifics. However, Allied Telesis has several case studies of school installations. It’s always best to go with a proven network solution.
The case studies are available online. Here is one about St Swithun’s school in England which links together several schools to a central location and single internet connection point.
There are other examples such as ‘The loop’ in Nelson, New Zealand. This is a fiber optic network.
Here you can find all of the case studies: