Starting off, I have the Kandalf, which is exactly the same as that case, but has a front door, and it is a beautiful case, very roomy, and is the best case I have. You may want to consider getting the aluminium version though, just makes it a bit easier to move around.
The raptor isn't actually that fast. Nice benchtest here: http://www.anandtech.com/storage/sho...px?i=2577&p=11
DFI is the best for overclocking, as proven by the multiple extremely high overclocks done on it.
I personally would get normal XP home or pro, what ever takes your fancy
I would get the cheapest ram possible (that is PC3200, and comes with a warranty) and get 2gb's of it. Preferably 2x1gb sticks.
For the graphics, this isn't alot over $300... http://www.newegg.com/Product/Produc...82E16814130247
I just brought a Hiper type R 580w PSu, and love it. PCP&C are meant to be the best. Antec, Hiper, Seasonic (just won laods of rewards) PCP&C and otehrs are the best.Very wise not to skimp on them. My friends cheap PSU caused my hdd to catch on fire.
If you want water cooling
But for air, the Zalman 7700cu or aero flower. Don't let the processor get too close to 60*C. Preferablie under 50. Also, buy some artic silver 5 thermal compound, as it is the best one out there.
And if you don't mind waiting half a year, the AMD M2 socket will be realeased.