First off I wanted to add a couple of new requirements to the design:
11) I want to be able to send EMail to myself. These Emails would be status Emails of scheduled processes.
12) I want to have a web server running. This server would be using primarily for research and development.
Secondly, I have determined that I will use TiddlyWiki for my internal wiki software. After spending some time analyzing the different capabilities of these types of software I decided that while I do want to spend some time playing MySQL, I did not need the complexity of a database back end for my internal wiki. I will use the database for other uses in the LAN.
Lastly, I have started to price out the first of my LAN servers. I think I can build a dual processor, 1 GB RAM, 1 TB disk space machine for about $1000. Now I just need to convince the financial manager of the house. :)