Have you read Linux Home Networking
(or the accompanying book, the Linux Quick Fix Notebook)? It won't give you any clue about which distro to use, if that is the question, but you should read it anyway.
And regarding which distro to use, the one criterion that I would suggest to you is that you want the distro to have support (ie, continued availability of, at the least, security patches) for as long a time period as possible. When patches are no longer available, and you no longer get updates, you will have to upgrade, and that implies setting up everything, again, and you don't want this to happen every five minutes.