Help Updateing Home/Work Server

Hi im looking for some advice on updating my Home/Work server. Its a very simple server. I have 4 Servers.

1.File Server
2.LAMP Server
3.Gateway Server
4.Linux server SSH Things like that

1. 3com 24 port 10/100 Switch

I have 20 people users on my network. We use the file server for Everything all the time Movies Iso Large files.. U get the point. I was thinking of Getting 2 10/100/1000 cards for my file server. And a new switch something with 2 1000 up links ports. Does this sound correct. I’m looking for advice tips ideas anything looking to spend in the $200 range