NAS/Linux media server advice needed

Hello, 

     I'm currently running a 14 workstation/rendernode farm - all peer to 
peer networked. I added a couple of 1tb NAS servers to get around the 10 
computer limit in Win XP pro. 

     The NAS drives are overloaded and running too slow when we're busy. I'm 
looking to replace them with a server and dual 1gig NIC cards. Is anyone 
running a Linux server for their files / renders frame? Or do I need to stick 
to windows and get Server 2003? - 

   I'm only planning to use the machine as a file server not as a render 
node. 

   Thanks for the input,