I have an X2 4200+ AM2 Low power CPU running on that Gigabyte ATi 690G mobo with integrated graphics. This will run upto 1080i res for me without problems (should even reach 1080P but I dont have a display that runs that high). ATi do make the 690G chipset for Intel as well but I have not seen a review of it (I had a spare AMD so used it).

The E6600 cpu should provide enough power to decode blue-ray etc without to many problems (my Q6600 does it and it does not even break a sweat) but that chipset DOES NOT support H264 acceleration which is a BIG drawback.

Just kit it out with enough ram (reccomend 3GB if going for Vista and assign 512-1GB to the graphics if you can) and you should be fine, if you have problems then you could fit a new graphics card. What you really need to look for is H264, VC1 and Mpeg2 acceleration in the graphics hardware which the ATi chipset provides.

I have a WD GreenPower 1TB drive in my HTPC and after setting the AAM to quiet I cant hear it. Even with the drive left at default it still only makes very quiet clicks.