re: Easy/Cheap way to connect TV to external speakers

The last item is the only one with an amplifier to drive the speakers but you'll need a 120v to 12v converter to power it and an rca cable to connect to the tv (and speaker wire). You could look for stereo amplifiers that run on 120 directly. Depending on your available cash and space, you might want to just spend the cash for an av receiver and couple of bookshelf speakers for a significant bump in audio quality and it'll be able to run the surround sound speakers too. You could add a center channel and subwoofer later too for 5.1 surround. Using tv speakers will give your ears aids.

Look up zeos on Reddit, he has a bunch of suggestions and discussion of budget audio setups. He has links to a few small amps if you just want to power the ceiling speakers.