Why spend so much on the build and get a decent GPU, but not a better one? I would check out a 4870 (1 GB if possible) or even a GTX 260. It seems like a huge monitor and a lot of $ to spend and not get a better GPU.
+1 to the HDD suggestion. WD all the way (check out the 640 B HDD)
If there is going to be no gaming, then something that will provide smooth HDV playback, which these days is not much at all. I would suggest a HD4670, or an HD4830, both really arent too much and will be plenty.
Hey I like your build,
Just a thought though you might want to go ahead and buy a couple more drives to build a faster raid array... With two drives before you know it your transfer rates will drop to about 100MB's a sec. HDV with run fine on that but as soon as your start makeing high quality graphics with alpha's and if you can uncompressed codec's your two drive array won't be able to handle anything. Trust me i just ran into this problem with a G-technologies extrernal esata raid enclosure (2x 1tb drives). If you can afford it put in some speedy drives maybe even 4 of the new seagate 7200.12s They are fast, cheap and run cool and quiet... Just make sure you give them plenty of burn in time. Cuz the 7200.11's have been iffy at best.