Spooky,, I bought a GT60 from Richer Sounds yesterday and a SB400 as well! So far really good. Its quite wide/long but if its the 50" TV it wont look out of place.
It offers a wonderful variety of sounds but the styling is not so cutting edge. Just be careful that the soundbar does not block the bottom of the screen where the remote 'window' is located. The Sonus Soundbar is wonderful as is the Philips 9100 but both are a step up in price.
I think the JBL will be a tight fit under the screen. The LG 4530 is pretty slim, the Philips too as is the Yamaha 2200. Try the Denon 'plate', this gives out a great sound for £250 or so and the TV can rest on top of it!!