You could also look at previous use of new technology that was going to "transform lessons".
Did your school buy a load of DSs (DSes?)? If so, are they still regularly used? In that case you've at least got a chance of getting some use from the iPads. If, like 2 of my schools, they are stuck at the back of a cupboard after the novelty wore off then you could probably save yourself a lot of time and money.
I'm sure someone has posted this story before, but if not: The school that swapped its laptops for iPads… and wants to switch back | PC Pro blog