Low Power, affordable options do exist.
It was just released but the Asus E35M-1 Pro sells for $140 on New Egg (sold out) but still available on Amazon for $163 -
It has an embedded processor (Zacate, 1.6Ghz Dual Core) with very low current draw.
Here some reviews -http://www.overclock3d.net/reviews/c...ro_micro_atx/1http://www.eteknix.com/motherboards/...rd-review-727/
It only supports single channel memory so with one stick of 2GB memory you should be fine, unless your going to be using Media Browser and cache your images to RAM. In that case I would opt for at least 4GB.
You have a MB/CPU/RAM listed for $170.
That board is passively cooled, I have your requirement for silent covered. But I need to know a few other things. If you need expansion slots, you might want to wait for this board to return to stock at New Egg or wait for the cheaper model that doesn't have USB 3.0.
If you don't need expansion slots and it doesn't sound like you need them, then there will be sub-$100 AMD Zacate boards. The ASRock and Jetway mITX verions should be available by this weekend from New Egg. Both promise to be under $100.
The Jetway NC85 will be the cheapest of the dual core Zacate boards. If your going to use HDMI, then its perfectly for HTPC duty. You can buy cheap SODIMM memory for it, it has a miniPCIex1 slot so you can use a mini WiFi-N card or mini HDTV Tuner, that will leave your USB ports open.
For cases, I am looking to build a AMD Zacate based HTPC as well, so I have opted for this case - http://www.szrealan.com/En/ProductsV...px?bid=6&id=68
Its being sold by Habey here in the US (Black and Silver versions), you can find it for $68 on both Directron and Newegg. It comes with a Pico PSU (120w), so you have a power brick that comes with it.
I have priced out a similar build (using the Asus board) and it comes out to about $326 - http://www.avsforum.com/avs-vb/showt...3#post19958423
that's tax and shipping.
Add $70 for your BR drive and you're still under $400 ($396)
Is there any special reason why it has to be Windows 7? Don't get me wrong I used Windows 7 and only Windows in general and don't have much experience with anything else. But you didn't say if there was going to be and DVR function with this build. If not, then running Windows is really not needed.
You can get the job done with Ubuntu + XMBC and Boxee, all free (though some content on Boxee like Netflix will cost extra) and a quick Google search turned up MakeMKV for Blu-Ray playback - http://www.makemkv.com/
You might be able to save $10-20 off Windows 7 Home but using the upgrade disc - http://www.winsupersite.com/article/...ade-media.aspx
I went from Windows 7 RC to Windows 7 Home using the guide on Paul's site and the Anytime upgrade download (no physical disc), which is $79.99 currently.
Edit - I didn't know you were in China, if so then most of the AMD Zacate boards should be available. Most them them won't be available in the US/CA until late Feb/early MarchEdited by djfourmoney - 2/10/11 at 7:45pm