I am thinking about building a new System based on AMD phenom II X4.
My main task with the computer are:
a. simple surfing.
b. programing Java/PHP / other c. Video editing. (Full HD encoding decoding)
I am thinking about this 2 Systems :
Phenom II x4 Quad-Core 965 Socket AM3 3.4Ghz 45nm Box
Arctic Cooling Alpine 64 Pro CPU Fan For s939,AM2,AM3
The PSU you listed is actually probably the strongest of the 3 . Wattage labels can be misleading
If these processes are going to work your processor very hard and ambient room temperature often gets above 30C I would recommend a good cooler. Here is a great source for cooler comparisons: http://www.frostytech.com/top5heatsinks.cfm
For larger power draws such as yours one of the long-time favorites is the Corsair 650TX. It's a Seasonic-built unit, very quiet, and can take the heat.
Antec TP-650 is a newer modular design that is very efficient and also quiet.
The Seasonic X650 is the ultimate PSU with incredible efficiency, but quite expensive.
Here is a partial list of PSUs that might fit the bill... note the actual 12V amps and links to reviews.
A budget option would be the Antec EA650, possibly.
Given at least a 300W continuous draw and probable load spikes, combined with mission-critical operations, I believe you want a very stable and efficient PSU. Power is probably not cheap over there also, so saving 5% could be meaningful.