I'm not going tp pretend to be an expert into such things, or an audiophile, but just to make a couple of points.
My set up is PS3, Logitech z906 speakers, and a wireless adapter.
http://www.logitech.com/en-gb/speakers-audio/home-pc-speakers/devices/speaker-system-Z906
I sort of fell into this as there was a 40% off everything promotion on the Logitech site and I thought I might as well get something half decent.
The wireless adapter is a gem, it turns a shitty old phone\ipad into a booming audio system.
A PS3 beats the pants off a blu-ray player.
I have the five speakers lined up in a row under the TV, with the sub -woofer hidden behind the tv. This arrangement is aesthetically as questionable as it is audiothetically (new word but you know what I mean). I am not going to redecorate the room to hide wires, or leave wires trailing around skirting boards and up walls. The sound is a massive improvement on what I had, and is as good as I'd hoped for, but is not taking full capability of the setup. If you are not going to build a decoration cost into your budget, get a good home theatre soundbar which is designed for my setup. Or go for something like the Monitor Audio range that is in your face and not meant to be hidden.
Make sure you have every type of input. I use 2 optical inputs for the UPC media box and PS3, and 3.5mm for the wireless adapter. I have no real need at the moment for a hdmi input, which is just as well, as the system doesn't have one, I suspect I may regret not having one in the future. Make sure whatever you get covers everything you'll ever need.
Also be careful about declared aggregate power outputs - a lot of these things have a huge power output going to the sub-woofer which adds nothing to the quality of sound other than rattling the house at a tense moment during a film. The logitech system sub-woofer is 165 Watts, I imagine that LG system you listed is probably 300/400 watts. I find I need to tone down the 165. If you let the LG system run uncontained, it might be prudent to have a structural engineer check the house foundations. Having said that, it looks a better buy than I got.
BTW I bough an LG TV on Amazon a while back. I emailed the LG support crowd in Ireland and they will support the TV directly without having to send it back to Amazon if there is a problem. Not quite as good as a bricks and mortar store here but worth noting.