Plenty of room for improvement here IMO.
Maybe swap the DS3 for the 650i board? I believe it's a better clocker, and supports SLi.
If you can spare it i'd stretch to the Lian-Li PC7+, it's a much better case.
I'd also consider finding the money to go up to one of the Corsair PSUs, they're fantastic.
Swap the DVDRW for the SATA version? That way you could do away with IDE cables altogether.
Not sure what the E6400 would offer you over the E6300, especially if overclocked. You could save a bit of money and lose little, if no, performance.
And finally, if possible, stretch to the PCIe BFG 7600GT. It's really much quicker than the X1650 Pro, which is a poor card for the money.
For all these changes, I don't think they would affect the price much, but you'd end up with a much faster, cooler running system.
[Edit] Here you go...