I dunno, but personally i would go ahead and buy a really good comptuer now and then buy additional accesories down the road. The onboard DFI sound is already pretty good (im still using it) and unless you REALLY need a new monitor i would keep it. Since you want too overclock try this out:
Western Digital SATA2 250gb hdd
Antec TruePower 550W
Logitech X-530 speakers
Corsair 2x512mb VALUEram
This was hard because you wont be able too overclock with it very well but i was kind of running out of money for your budget....lol
Then use your old cd/dvd drives and case.
The total comes out too $964.96. You can mess around with some of the stuff too lower the price and then get other components but i think you should get something more along the lines of that.