I would not trust my build to that power supply. Just my opinion.
If you can squeeze it...I'd say this would be better.
http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.432095
Also, the board you picked is ddr2 ram. While we are at it, let's see if we can find something more.
http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.436269
How about this? That is 20 bucks more...but gives you an x3 instead of a dual core. A little more future proof.
If you want to spend 100, this is a better video card
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125236
Though since your budget seems to be tight. Only a suggestion. The 9800gt is not that strong a card for today anyway. How about going to a 4670 with an eye to upgrade?
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125277
That is 70.
But for the better PSU and case it's 60. And about 20 more for the better cpu and board.
I ran the numbers again, and if we did those modifications, better case/Power supply, better CPU, and the 4670 you are at 398.99.
However, with a 9800gt, you would be upgrading later anyway most likely. Here you'd have a better CPU more capable in the future as games become more multithreaded. With a 4670, it's not as good as the 9800gt, but you won't have as much into it.
With the better power supply, you shouldn't have to worry about it killing your system.
Also, I currently have a 9600gt, 2 gb of ram, and a dual core chip and it runs empire total war and napoleon decently actually. The 9600gt is roughly equivalent to the 4670. So it will do some games now, but when you upgrade later, sell it for 30 bucks on ebay or something, and you are not taking a huge loss.