Looking to make 2000 movie HTPC

What should I use to transform to a HTPC? Sorry kind of long!!!

Here's what I got now.

3X 400 Disc Sony DVD Changers and digital cable hooked up to 70" and 42" HDTVs through a matrix 4X2 switcher.

Well I'm full! 1200 movies was passed a while ago. I am looking for the space for about 2400 movies and all my music (100GB of mp3s) to throw into Windows Media Center and use the computer for that and for use with recording tv in media center.

So here's what I'm thinking:

I need a board with 6 SATA slots to do 6 2TB hard drives (2TB should probably equal 400 DVDs by my math, 5GB X 400 = 2000GB) if it is less by a little, no biggy

I want to have DVI and Optical Audio for now and when i upgrade my 42" tv, I will buy a new switcher with all HDMI switching so I want HDMI also.

That is about it. This computer is only going to be for movies, cable, and music.

Tiger Direct has a Biostar TA790GX A3 Motherboard w/ AMD Phenom II X4 965 CPU w/ Fan Bundle for $379.99
this would have the 6 SATA for the hard drives and all the hookups I want.

From there?
Memory?
Power Supply for all those hard drives?
Cooling?
Am I going to set this up and find out I'm an idiot and this can't be done?

I'm in over my head.

Please help