You can save a few $$$ on the psu and a wd black 500gb you don't need a 700watt for your build..
Also this deal is pretty good amd p2 955 be + 4 gb a-data ddr3 1600 for 250..
NCIX.com - Buy NCIX Gaming Bundle Deal AMD Phenom II X4 955 Black Edition CPU & 4GB A-DATA DDR3-1600 C9 - 955-4GB-1600-C9 In Canada.
If you like Asus you can try the M4A79XTD EVO it has the 790X chipset you're looking for..
NCIX.com - Buy ASUS M4A79XTD Evo ATX AM3 790X DDR3 2XPCI-E16 2XPCI-E 2XPCI CrossFireX SATA Audio GBLAN Motherboard - M4A79XTD EVO In Canada.
Also I believe the 5770 is suppose to be as good as a 4870 but lose to the 4890.. I could be wrong though..