To second DoctorOhh: there is very little point in providing the wireless connection in a headless client. Doing interesting things with a connected device requires talking to calibre's gui, because calibre is in charge of connected devices. It is true that certain automatic tasks such as reading list and news sync could happen without user interaction, but this is a rare case.
If you really want to enable the wireless driver on a headless client, then something like the following might work. I haven't tried it myself.
1. On a client with a "head", start calibre. Set all the parameters you like, including auto-start the wireless connection and (probably) the content server.
2. Copy the configuration directory to your headless server.
3. On the command line, start "calibre" (not calibre-server) using the command line option or env var that specifies the copied configuration.
This will work only if calibre believes that it is talking to a GUI. You are probably using xvfb to simulate a display. I have no idea if it also simulates a keyboard. In other words, I don't know if the calibre GUI will actually start on an xvfb configuration.
On the other hand, CC's content server integration should work fine with a headless server as long as the server is calibre 0.9.0 or better.