Which is better? Please help!

[jcook71506]

Hi all,
I'm kind of new to the Home Theater world. I got me a nice setup so far, got a 50" 1080P Plasma, 42" 1080P Plasma, Blu-ray player, Comcast HD/DVR and a 5.1 sound system (want to upgrade to a better system with seperate receiver). I am debating on THIS SYSTEM. It's a 5.1 and I have room for this and it's cheaper in price, but do you think this is a good investment as I am on a budget. Is the receiver alone capable of future upgrades? The reason I ask is because some receivers have the speaker wire and then the speaker wire that you look like plug outlets and eventually would like to upgrade the speakers in the next couple of year. I would like to get a good amount of responses within the next week or should I go with THIS SYSTEM which is a 7.1 system, but will I get the use of all the speakers when watching a Blu-ray considering most movies and music only use 5.1 audio? And where would I put the other 2 speakers? I was thinking on the floor, but don't know. Please help! As I would like to get this within the next 2 weeks!