LED TV’s ARE LCD TV’s. The difference is that LCD TV’s are back lit by what amounts to florescent bulbs. LED TV’s have an array of usually hundreds of LED’s lighting the screen. Some are Dynamic LED TV’s meaning that they change the brightness of the various LED’s behind the screen depending on the picture. This increases the contrast ratio (the difference between black and white) but this can come at a cost. An example is the movie, Stargate Continuum. It opens with a big space scene so the LED’s turn off with the result being that you can’t see most of the stars. They are, however brighter than LCD’s and usually more expensive. There are LED TV’s that are not Dynamic. That is, they just turn on and show that space scene just fine but with less deep blacks. LCD TV’s show the stars, also with less deep blacks. Plasma has no problem with that scene but if it is in a room with lots of light or windows, you see the reflections really well on the screen.

As for close captioning, before buying, ask to see it. I would check to see if the text is crisp and if it turns on and off fast. The scrolling ticker of a sports news channel is good for checking the response time of the LCD pixels. Some look blurry to me.
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A surround sound system, while wonderful, is both expensive, and time-consuming to install. If you want to do it right, you’ll have to run cables through the dry walls, screw in your speakers around the room, and configure it. So, it’s really up to you.
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