Budget Range: $850 Including Rebates; Before Shipping
System Usage from Most to Least Important: Window Media Center DVR with 2 OTA tuners/ AVCHD home video editing/ Video Encoding via Handbrake software/ web browsing/ MS Office.
Are you buying a monitor: No
Parts to Upgrade: All parts except Silverstone GD05 HTPC case
Do you need to buy OS: No (Windows 7 64 bit)
Preferred Website(s) for Parts: Newegg, Amazon
Location: Newark, Ca (San Francisco Bay Area)
Parts Preferences: Intel CPU, Western Digital HDD storage
SLI or Crossfire: ?
Your Monitor Resolution: 1280x768
Additional Comments: I'm planning on building an HTPC running WMC 7 24/7 as an OTA 2 tuner HD DVR, and hopefully be able to use the same system to web browse, use MS Office, and occasioally edit home movies nativelly in AVCHD format. My first question is whether or not this is going to be possible an a budget of $850? Second, if it is, is the system I am proposing below work for my needs? Will I be able to overclock with the proposed low profile cooler? Any advice is welcome. I'm not new to technology but this is my first pc build from scratch.
You've definitely made a good choice for your CPU regarding video-editing and if you can create sufficient airflow in your chassis you'll be able to do some overclocking as well. It's quite a large HTPC chassis so you should be able to...
You could go for a cheaper motherboard, you don't need Crossfire etc. but as you're running it 24/7 I would definitely choose for a high-end motherboard so you're choice isn't too bad. If you can find a mATX motherboard that offers enough expansion slots for you, that might be an option as well - they usually consume less power than their full ATX counterparts.
Your PSU is a bit overkill right now without a GPU... without a dedicated GPU you'll be fine with a 400W or even less (depends on your overclocking and other needs though).
However, I would definitely recommend a better GPU. The onboard is really slow - you might even see it when playing multiple video or AVCHD streams. If you go for a better GPU that might even safe you some time during transcoding work. However, as you have about $180 for the GPU, a dual tuner and an optical drive... there isn't much money for a graphics card.
It depends a bit on the software you're using but the NVidia cards with CUDA cores do quite a good job in general. An NVidia Quadro would be the most optimal choice but as that is pretty much out of the question (expensive), something like a 550Ti would be you best choice I guess - previous generation though relatively cheap and has 192 CUDA cores.
As I'm from Europe, I can't give you any advice on a ATSC OTA Tuner I'm afraid...