Some opinions on my current situation.

You are looking at 5 pallets of school e-waste, you will definitely need to worry about getting on and off what ever kind of truck you will use. Now that S10 you have should be able to pull a trailer, you could rent a U-Haul trailer but you will need to make 2 trips, unless you are able to put a 6X12 enclosed behind your S10 and off-load the pallets into the trailer, but then you need to worry about the weight, I loaded a 6X12 from U-Haul to the gills, half of it was whole towers and the other half was general e-waste, and it was definitely over weight and my full size suburban felt it.

If I were you, I would talk to the school guy and see if you could do things a little different and just start with 2 trips or so with a trailer. It really shouldn't take all that long to break it all down. 5 pallets should only take a couple days for break-down and turn in. Trailer would be the most cost effective. When you rent a truck, sure its 20 bucks a day + mileage + gas, it all adds up. Rent a trailer for 20 bucks a day and its just the trailer, and rent an enclosed one and break down in back of it.