Need Wattage advise

[grufus]

Hello all
I am looking at ordering a new PC for home primary use will be some gaming Fallout3, Call of Duty etc. and general purpose browsing working from Home et el.

Current Config selected is as follows
2 HDD's x 1.5 TBs
4 GIG RAM DDR2 800
MoBo ASus P5Q-PRO
CPU: Intel Q 9400 2.66 Ghz QUAD
1 x DVD Burner
Graphic : Unsure either 1GB HD 4870 or IGB Nvidia GTX 260

Need advice on Case:
I like the coolermaster RC-690 http://www.techpowerup.com/reviews/CoolerMaster/RC_690
It apparently has 450Watt PSU. The techguy in the shop suggested I needed a higher Wattage and is recommending a Case along with a separate PSU > 550 Watts

I like the RC-690. Will it handle the load. One of the choices I am considering is keeping the RC 690 but getting a lower wattage Video card like maybe a Nvidia 9800GT 1 GB

Any Ideas

 

[wathman]

Can't you just order the case you like without the PSU?
http://www.newegg.com/Product/Product.aspx?Item=N82E16811119137&Tpk=cooler%20master%20RC-690

then you can get a nicer PSU like a Corsair PSU in the 500 watt range. The 650 watt one from Corsair is a nice one if you can budget it, has been going for $79 after rebate at newegg lately.