they should do, though some PC games and films may only be designed for 5.1, blue ray should be 7.1 but tbh when u go to an electonics shop to buy a home cinema most are 2.1 or 5.2 very few are 7.1 simply cause its soo many speakers, 5.1 gives 5 directions of sound which is enough for the average room
like Jay said with 7 speakers its a lot of wiremanagement, id stick to 7.1
this is how id have the perfect set up...
Video:
From PC, either HDMI or DVI
to TV, HDMI
you can buy the cables on ebay
Sound:
Optical from PC to Optical in home cinema
also if u have an ATI card some let the card take the sound from the motherbaord using the HDMI which is again a 7.1 signal... so if u had the right stuff u could just have a hdmi going from PC to TV carring sound and video
and then from TV to home cinema optical
this is better as u may have a PS3 bluerayplayer ect all using HDMI to transfer thier 7.1 sound so the telly can transfer all thouse sound signals over the one optical wire
because tellys have 2-4 HDMI sockets but devices only have one optical