I recommend finding a networking kit for your systems, almost all the manufacturers have on e or more, Netgear, D-Link, Linsys, etc. This is what they normally contain:
2 NICs
1 HUB or Cable/DSL Router
2 CAT5E Cables
This will give you more expandability, and it will allow you to share the broadband service easier. I am set up that way, and I have 3 systems on the HUB, and my Notebook can connected whenever I need to, and they all share the internet.