i mean what i of speaker do u use?
i dun know much of speaker that support optical, but the one that does will cost a boom.

I'm going to buy home theater system but i dunno if any of them support optical in. I'm currently using creative extigy to get 5.1. But i dun want 10 speakers to be in the room. 5 speakers connect to extigy and other 5 are home theater.

Just stay away from those HTIB with dvdplayer included. Most of them dun have any optical inputs. 

Actually bro judge, you can get an optical splitter for about RM 80 on ebay inclusive of shipping. That will take care of your optical needs, and there's no degradation : remember, optical = light!

BTW, the problem with HTIBs are not optical ins, it's coax. I have an upscaling DVD player with coaxial output, and since my HTIB receiver only has optical, I'm screwed unless I buy an optical--coaxial converter.