You could clearly spend less on the case if desired, but if you want the HAF X, who am I to argue?
The only real question I have is on the hard drive. The Caviar Green will definitely work, but it's going to be substandard as a boot drive. Caviar Green drives are 5400 rpm, though Western Digital goes to great lengths to not put that in the advertising. You might want to look at getting a 500 GB Samsung Spinpoint F3 or Seagate 7200.12 for the boot drive, and then getting the Caviar Green as a storage drive.
I'd only pay the extra for a Blu-ray burner if you know he's going to be burning Blu-ray discs. A standard DVD burner should only be $20-30, while a Blu-ray burner is north of $100. I wouldn't pay that much for one right now unless you know it's going to be used.
I think you could probably go lower than the 5750 for the graphics card. A 5670 should be adequate, you might even be able to go lower.
In theory, if you got a smaller/less expensive case, lost the Blu-ray burner, and went with a smaller graphics card, you could probably afford a 60 GB OCZ Vertex 2/Agility 2/Mushkin Callisto/G.Skill Phoenix Pro/Corsair Force SSD.
I would suggest a RAID 0+1 config, since you will have lots of data ( hence raid 1, to make sure you dont loose it) which you will need to access quickly( hence the raid 0).
so you will need 4 HDD's in total.