^If you can play 5.1 audio to your surround sound system now then you will be able to with your Bluray drive. You need to make sure your existing PC has the CPU/GPU capabilities for 1080p Bluray.
You should be able to find & download some test files and play them. Use XBMC or other free player software. It won't cost you anything. If all is good, then you could go with a BR drive & player software. If you want to save money, buy a read only BR drive.