I wouldn't recommend building pcs if its being paid for by the school or someone else. There is that small liability issue of anything bad happening. Better to just buy prebuilts just to have your butt covered since the warranty is for the whole entire system and much easier to explain to the principal in case something bad do happens.
Or just buy tablets that support keyboard hookup. --- Intel i5 4670K | Corsair 16GB DDR3 | Gigabyte GTX 770 4GB | ASUS 27" 1440p Corsair 480GB SSD | WD 4TB HDD | Fractal Design R4 | Corsair 750MX | Win7Ult 64