I initially installed a very large inverter wired for whole rig use which I found I rarely used since I power most heavy current demand items via onboard genny anyway.
Decided to just install a smaller 300 watt pure sine inverter in our entertainment center, discovered the 12 volt dc socket was unable to feed enough power to keep inverter from screeching it's dissatisfaction. No biggie as I just ran heavier wire directly from battery bank.
One of our favorite mods, it powers our HDTV, HD satellite, Bluray/Xbox, Bose and laptops, even has a couple of USB sockets for charging portable devices. Although it is only 300 watts it is able to power these items simultaneously.