Suggestions on Setting up my system

[skatinkamel]

I'm currently in the process of setting up a home theater in my basement. I have a Samsung Lcd which i am satisfied with but am now moving on to a stronger audio system. I have been researching receivers and am unsure whether i should make the move to 7.1 or stick with 5.1. Also i am unsure of the brand i plan on purchasing. The best looking receivers ive seen are these:

5.1:
Denon AVR591 which is about $350
http://www.usa.denon.com/ProductDetails/5302.asp

Yamaha RX-V367 for $230
http://www.yamaha.com/yec/products/p...&CNTYP=PRODUCT

7.1
Denon AVR890 for $520 which is obviously on a great SALE!
http://www.usa.denon.com/ProductDetails/4918.asp

Sony STR-DH710 for $300
http://www.sonystyle.com/webapp/wcs/...specifications

Sony STR-DH810 for $400
http://www.sonystyle.com/webapp/wcs/...&SQS=str-dh810

All of these interst me ,but i am unsure of which to choose. My price range is limited to about $1000 to $1400 for the whole system. My bluray player is a Sony BD-350 which doesn't decode DTS-MA. Any suggestions would be helpful. Thanks in advance