In my country P7N+two GF9600GT cost about 260 pounds. Single HD4850 costs about 110 pounds with some % off. I'm little tight on budget -_- I already squeezed this configuration to minimum due to money needs on other things. Besides P7N is being praised my many websites, that's why this choice.
And in my country not every single psu is available. I have Zalman available, but those cost load of money. Thanks for help, much appreciated