Application Server

I work part time for an infant school running an NT4 network. The teachers need to run various childrens programs in the classroom. At the moment each class has a set of CDs which are, predictably, becoming damaged. The aim is to centralise the CD software to a central PC/server and download the package as required to the local PC.

Is a server seperate from the PDC required or can the PDC provide both services ?
How so I set up the local PCs to load the packages on demand ? I assume that he entire package should be loaded to the local PC rather than rbe run from the server.

All advice gratefully accepted.