Server requirements to run a network of ~100 iMacs as thin clients?

Hi, I'm just starting a system administration internship, and since I didn't know much about the server side of things, as a learning project I was assigned to figure out whether transitioning our network to thin clients would be possible. Currently, we have almost 100 iMac workstations for the students and teachers which are standalone but with the user accounts stored on our server. The school is thinking of transitioning to using said iMacs as thin clients, having them boot off the server, since that would make them easier to maintain and they would all then have the same apps installed, etc.
I know how to make a netboot image and how to have the iMac boot from it, the question is would it be feasible, what are the performance requirements? We currently only have 1 server, a Mac Pro with a 2.66GHz quad core Xeon and 12GB's of RAM. The students are only supposed to use the workstations for basic tasks, web browsing and document editing, etc. Would it be possible with what we have? If not what would we need, server-wise.

Thanks in advance! As I said I'm just starting out with this stuff, sorry if it's a stupid question.