Advice needed for nontraditional htpc build

[Sozen]

Well I should probably preface this by giving a little info on what I'm going for in this project. Currently I'm using an old laptop hooked up to my TV for the watching of anime, and I'm rapidly running out of room/power to play the newest encodes, and my dvd collection is getting out of hand last count I'm over 400 anime dvds, and that is my other problem. I have blu ray ability through my ps3, but I'm also looking into backing up those files as well so I'll definitely need storage. I saw this build on AVS and I'm submitting this for the opinions of the board members.

# CPU: Athlon X2 4850e ADH4850DOBOX 2.5GHz Socket AM2
# CPU Cooler: ZEROtherm BTF90,
# Motherboard: GIGABYTE GA-MA78G-DS3H AMD 780G chipset ATX,
# Memory: A-DATA ADQVE1A16K DDR2-800 2 x 1GB Kit,
# Graphics Card: Sapphire Radeon HD 4550 GDDR3 512MB,
# PSU: Corsair VX450W CMPSU-450VX,
# Case: SilverStone Lascala LC17 SST-LC17B,

I'm trying mainly to play the newest codecs, and I also want the ability to pass audio, and video through HDMI straight to the tv and eventually through a newer receiver. My main concern is storage as I need to back up some dvds that are actually degrading, and my better half is tired of 2 closets being taken up by discs. I consider myself fairly handy but I don't need the newest craziest parts and would like to stay around $700 before OS
I also already have some hard drives so I've not listed them obviously in the parts as I have 2tb ready to go for internals and the case seems to be able to run supposedly 6 though i think the sound/cooling would be a definite problem if I went that crazy. Please any advice would be most welcome, and especially any suggested builds/more things to look at would be much appreciated.