HTPC - Atom 510 w/ 4850 single slot

[NI3]

To buy:
Board (for sound & video cards): Zotac NM10-BE
Case: Custom, or Silverstone SG05-b

Already owned
Video Card: Sapphire 4850 (Single slot)
Sound card: Sound Blaster X-Fi Titanium
2x1TB WD green (non raid)
Bluray drive
2x1GB DDR2

The resolution is 1280x720 right now, but will be increased to 1920x1080 within a year. Will this be able to play blurays, netflix streams, and maybe L4D2 (@ low res w/settings)?

If not, I will go AM3 mATX. Really my problem is that I have not used an atom since 2009, and it was an HP mini 1000, single core, single thread, GMA 950. I haven't had experience with these chips for a while, so don't know how well they are paired with a 4850.

I also have a 4650, but I am not sure how well it would fair regarding hardware acelleration.

[neojjjk]

your budget ?

[NI3]

Max I would spend on this is $350, but I would prefer to keep it under $250. Every dollar I save goes towards a triple monitor setup.

Everything that is already there was taken from my previous HTPC, who's CPU and motherboard (athlon II X2, ASrockk 770) have been donated to my aunt, who literally only uses facebook, and hotmail. I was hoping to build something quieter, more energy efficient, but mostly smaller.

[LarkStarr]

if you're okay with the GPU decoding HD content, should be gold.

[supaflyx3]

along as you use DXVA it'll be fine for HD content, and L4D2 should run fine at medium-high settings.