Two 160 or 250GB WD Caviar's in RAID 0 would be just as fast, approxamately the same price and have 4 to 7 times as much space.
Nice video card.
I would step down the CPU to the 3700, its cheaper and a simple overclock will easily get you to the 2.4GHz of the 4000. You can get an easy 2.7+ GHz from that. I have one, trust me.
Also, I would recommend getting 2GB of RAM, it will really show in games like BF2. This is what I would suggest.
I believe that will still be in your budget.