Phoneline Network: Server vs. Router?

[A06]

I have a phoneline network of 4 computers, and I have a server in my
basement where the cable modem is. This is my current setup:

Cable -> NIC (Server) -> PNA (Server) -> Phone Jack
Phone Jack -> PNA -> Comp#1
Phone Jack -> PNA -> Comp#2
Phone Jack -> PNA -> Comp#3
Phone Jack -> PNA -> Comp#4

The problem is that my server freezes since it is a crappy old
computer. I was wondering about Routers..will it save me trouble?
All I use the server for is distribution of the Cable Modem.

Are there any Routers for phoneline networks, so it would be like:
Cable -> Router -> Phone Jack

Also, do routers have built-in firewalls?

Thanks!

 

[JCH]

Take a look at Linksys HPRO200.
http://www.linksys.com/products/product.asp?grid=34&scid=33&prid=176

 

[BudMan]

I used to have a similar set up to yours. Switched to a Linksys HPRO200.
Have not had any problems with it. The router cost about $130 a Buy.com.