First time comp build need help

I am planning on building a new computer in mid august before I go back to school. This is going to be my first build and my first new computer in 5 years. I have done a lot of reading on forums and this is the build i came up with:

Antec Performance One P180B
http://www.newegg.com/product/product.asp?item=N82E16811129017

GIGABYTE GA-P35C-DS3R
http://www.newegg.com/product/product.asp?item=N82E16813128048

SAPPHIRE 100196L Radeon X1950PRO 512MB GDDR3 PCI Express x16
http://www.newegg.com/product/product.asp?item=N82E16814102075

CORSAIR CMPSU-620HX
http://www.newegg.com/product/product.asp?item=N82E16817139002

Intel Core 2 Quad Q6600
http://www.newegg.com/product/product.asp?item=N82E16819115017

G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800
http://www.newegg.com/product/product.asp?item=N82E16820231098

Western Digital Caviar SE WD2500JB 250GB 7200 RPM 8MB Cache
http://www.newegg.com/product/product.asp?item=N82E16822144309

LITE-ON Black 20X DVD+R 8X DVD+RW 8X DVD+R
http://www.newegg.com/product/product.asp?item=N82E16827106055

http://www.newegg.com/product/product.asp?item=N82E1682...
http://www.newegg.com/product/product.asp?item=N82E16824001096

Total =1349.91 after MIR
I have about 1500 to spend on this build if necessary, although the less the better because the less I spend the more money I will have at school for other expenses so I would like to keep it as close to 1000 as possible.

The things I am least sure about are the case and monitor, but advise on any part is helpful. I will probably get a new graphics card in a 12-18 months. I also wasn't sure what cpu cooler would fit in the case because I haven't put everything together yet, so any advise in terms of coolers would be helpful. I plan on overclocking the cpu a little but I probably wont do it a ton because I've never overclocked before. If I decide not to overclock is the cooler still necessary/ helpful?


EDIT: It will be used for gaming, watching movies and school work.



I already have a copy of xp with upgrade to vista ultimate, although I might not upgrade for a little while.