I tried PC speakers for my TV last year but was disappointed. I connected the speakers via optical and when I did, there was no way to control the volume (the TV did not control the volume via optical). There was also no IR remote so I would have had to get off the couch to do the volume. I think these speakers are not optical so it may work differently for you but just something to keep in mind. If the speakers had an IR remote I might have been able to get the Harmony remote to control them, but the 'remote' was wired on the speakers.
I ended up getting a Yamaha Sound Bar this Xmas (
YAS-101 - Sound Bar / Digital Sound Projector - Home Theater Systems - Audio & Visual - Products - Yamaha United States .. got it for $200 Boxinf Day sale...could be out of your price range).
This one is on sale for less than half price, if its possible for you to swing it ($120 instead of $250):
Philips Sound Bar (HSB2313A) : Soundbars - Best Buy Canada
The only thing about a sound bar is that you need to be careful not to block your TV's IR remote sensor so you don't block the remote signals (the Yamaha I bought actually passes the remote commands through to the back which was pretty neat).