5.1 Channel output from STB(Tata Sky)

Hi All,

I understand that the STB(HD version of Tata Sky) produces 5.1 channel output through either HDMI or SPDIF options. I desire to connect a 5.1 HT system to enjoy the digital audio of the various TV channels. Please guide me with a a good HT system availale within 15k range ( with a SPDIF audio-in facility from STP ). Also please clarify that if I use HDMI cable to connect STP and the TV for audio and video output of the TV channels, will an additional audio output through SPDIF is still possible.