how does this sound? Are the components compatible with each other? I'm gonna buy all my parts from ebay. So, does this system sound good for $1000USD(Monitor case included)? Also, is there a too big performance difference between the CPU and GPU and RAM?
No, you have a non-OCable MOBO with an OCable CPU. Get a Z68 chipset motherboard, like the Gigabyte Z68X-UD3H. SATA III is yet to be saturated; SATA II isn't even fully saturated yet by HDDs. Modern HDDs only saturate 1.5GB/s.