You want your Zotac Zbox remote to control Zbox, your AV receiver and TV / PC monitor.
- Use HDMI 1.4 cables. You do not really have to, but you can prevent bugs, as searching for CEC errors can be quite time consuming.
- Be sure you use an AVR that officially (and fully) supports CEC. Many companies use different names for CEC; have a look at the CEC Wikipedia page. I can recommend the Yamaha RX-V373.
- The Zotac Zboxes do not provide CEC, so you need to get an adapter like this one. Installation in Openelec / XBMC is very convenient, you do not need any additional packages. You can configure it via GUI or use the cec-client (Windows and Linux) for debugging purposes.
- An also useful site for debugging is cec-o-matic.