I have heard the RT55 and it seems that they are good speakers, bit on the bright side but you will definitely need a sub with the kit as they don't have much kick in the lower end. But i believe you could have a better deal out there but i would recommend spend bit more as will last longer than that system.

Also as Mr. Peabody suggested, a new amplifier wouldn't hurt as there would be much more benefit with sound and the picture quality would be 1080 upscaled to all played through it.