I need to render an animation out at 4800 x 1080 for a screen.

You can set a comp to any size you want. You are limited in the frame size that will render with certain codecs. When rendering for specific screen displays you have to refer the documentation included with the playback device to figure out what settings and formats will work with their devices. You can't simply guess.

With some more information about your project and the output device, we can probably point you in the right direction.