Need help about PSU

[Danish Aslam]

TO ALL EXPERTS..

Umeed karta hun k Saare Experts khariat se hongay...

Actually Me Ek gaming pc banaraha hun... us k liay mujhay apki help ki zarurat hai...

Mere pc ki config hai...
Intel DG31PR...
Dual core E2180 2.ghz processor
2 gb ram (1x2)
160 Gb Hd Sata
Inno 3d 512mb DDR 2 Graphic Card...
250 Watts power supply ....

Me ye soch raha hun k Min 400 watts k power supply purchase karun...

khair yahan tak to mujhay malum tha, but mujhay ye pata karna hai k 400 watts ki supply standard lun ya 400 watts COOLER MASTER lun, ya phir Galaxy shop pe POWER MASTER 550 WATTS Dual Connector naam se ek supply hai, kia ye behtar ragegi (also for cooling)????

yahan mujhay bohat confusion hai k Gaming pc k liay kia 400 watts normal psu kafi nahe hogi..????

Aur is k ilawa Mujhay gaming pc k liay jo accessories required hon , so plz suggest me...

I am Really confused plz reply...

Plz help

Thanks in advance

Danish Aslam

Note: ( Agar koi gamer is baarey me help karega to i will very thankful to him.)