Copy the following code into a plain text document and save it as com.apple.SoftwareUpdate.plist in the above mentioned location. Make sure to edit the string of CatalogURL to your specific SUS URL:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>CatalogURL</key>
<string>http://PUT THE URL OF YOUR SUS HERE/</string>
<key>WebKitDefaultFontSize</key>
<integer>11</integer>
<key>WebKitStandardFont</key>
<string>Lucida Grande</string>
</dict>
</plist>
I suppose that if someone wanted to mirror the Official Apple SUS on a much faster connection, this hint would be beneficial to just about anyone.
Before anyone tells me what I didn't "know" ... I know that I don't personally need access to a server to have the Server Admin Tools installed on my machine, and that I can use them to manage the preferences of my local machine, specifically the SUS option.

