New system help

Hi, I am planning to upgrade and was just wondering what you thought about this. I'm not rich and the choice is limited where I live...
Core 2 Duo - either 6300 or 6600 depending on the money situation.
GeForce 7900 card
DDR2 800 ram (is it okay to buy A-Data 2x1024? I really don't have the cash to buy the best)
Asus P5W DH Deluxe - or MSI P965 Platinum - probably the Asus motherboard
X-Fi sound card
100 gb and 250 gb HDs
I have an Enermax 500 watt supply. Will it be enough? Will this system be balanced? Will it need extra cooling?
I'm not planning to get Vista or an 8xxx series and might get another of the same in SLi when the price of cards comes down. I want to play FSX with reasonable hope of getting it looking okay with tweaks etc.
Suggestions gratefully received!
Krigl
Core 2 Duo - either 6300 or 6600 depending on the money situation.
GeForce 7900 card
DDR2 800 ram (is it okay to buy A-Data 2x1024? I really don't have the cash to buy the best)
Asus P5W DH Deluxe - or MSI P965 Platinum - probably the Asus motherboard
X-Fi sound card
100 gb and 250 gb HDs
I have an Enermax 500 watt supply. Will it be enough? Will this system be balanced? Will it need extra cooling?
I'm not planning to get Vista or an 8xxx series and might get another of the same in SLi when the price of cards comes down. I want to play FSX with reasonable hope of getting it looking okay with tweaks etc.
Suggestions gratefully received!
Krigl