I doubt that you can buy a separate bluray/receiver where you can re-use your current 5.1 speakers. The best you can do is buy a bluray player and connect the digital output to your existing dvd player/receiver input, granting that it has one (coaxial or optical). Kung wala, you're stuck with your dvd htib unless you replace it with another. Btw bluray htibs are kind of expensive.