I am guessing that FX5021 is Rs10500 odd right ? Its not a good option for that money. What i would suggest is:
Get a Logitech Z5500, its far far better but a tad costly, at Rs18,000 its really worth the extra. As for the sound card, i would say go for onboard now, later you upgrade. The UD2 has both Optical and Coaxial outs so you can use that to get 5.1 on the speakers (Z5500).
Also, your board has 8ch audio, it is 7.1ch not 8.1
also, do you need the full PC for Rs60k ? (monitor,UPS,bla bla...) and what is the primary purpose of this PC?