Some televisions have audio out capabilities that allow you to connect an external speaker to the television's internal amplifiers. The more common audio out is a line level signal that would require additional amplification. The best fidelity will be attained by by-passing as much of the audio electronics in your television as possible and using external amplification. I would recommend that you use powered monitors to add surround capabilities. It will keep your system as simple as possible. Go to a Guitar Center, or similar store, and check out their selection. The brands (KRK, Event, Mackie) aren't well know in audiophile circles, but they are high quality products. A set of $400 (sale price) powered monitors can easily do the job.
BTW, it is my experience that surround sound really dosen't add that much to the movie experience.
BTW, it is my experience that surround sound really dosen't add that much to the movie experience.