Networks Please suggest a network topology

I have to build a network in a building from my student campus. I have 75 rooms to connect, 15 rooms on each floor, 5 floors total. The network will be used for Internet access, and the uplink will be provided by the university (2 Mbps fiber optic link + Ethernet Media Converter)

As always in such cases, money is a real problem, but anyway, here's what I was thinking.

I'm gonna install a 16 port cheap ethernet switch (Mentor or something) on each floor and wire the rooms from that floor to this switch.

In the server room (at the top floor), I'm gonna place an 8 port switch and drop 5 uplink cables to each floor switch.
The server (running linux / iptables, acting as a NAT router / firewall), will have two network cards, one of them connected to this central switch, the other to the media converter...

Some people suggested that I should place all equipment (server, switches) on the second floor in a locked room and run all cables from all rooms to this central location...but I would still need the same amount of switches, only a little bit more cable...

What do you think ? Any suggestions are appreciated !

 

Its really about the same, top floor or middle itll end up being about the same ammount of cable..