Google ADT-1 (Android TV) upgrade??

So I have this Google ADT-1 android TV and it need and an update but i don;t know how to create a android Rom... not sure if should go with a fully loaded android system or the android tv system... Serious freelancers have worked with and an Google ADT-1 before or has one... Mention that in your response. You can use this link for system files. [login to view URL] here are the specs: SoC – Nvidia Tegra 4. System Memory – 2GB RAM. Storage – 16GB flash. Video Output – HDMI. Connectivity – Ethernet, 2×2 MIMO dual-channel WiFi, Bluetooth 4.0. USB – 1x USB host port, 1x micro