I need to find a mediecenter kabinet, thats small, max 18.5cm in height, it has to be very quiet as well, ofcourse.

It needs to be HDMI compliant. Intel Viiv compatible. Anyone know something about creating a superb mediecenter?

Ill get a reward if create something nice

You mean like a Home Theater PC?

yeah we call that mediecenter pc here

Do you have a budget?

the budget is around 3000$ so it isnt an issue

I buy my parts at NCIX. I don' t know where you plan on buying these components but NCIX is still a good place to check out. Customers give a lot of feedback. So you can learn a lot about the products here.

http://www.ncix.com/products/index.php?minorcatid=104&subminorcatid=45

I' m looking into it.
Are you absalutely hell bent on having a HDMI out, because DVI is the same thing, it only requires an adapter? I' m assuming you' d want a sound card for superior sound anyways so having the sound seperately is a moot point.
http://www.jkcomputersystems.com/Assets/Pictures/items/AD-ATI-HDMI-DVI.jpg

Would it be ok to have that little converter at the back of the videocard? The real issue is having a HDCP compatible videocard.

I buy all my parts from newegg.com. I have my comp hooked up to my tv with a DVI to HDMI adapter.
You can buy media center PCs from alienware and dell and stuff if you don' t want to build your own.

http://www.newegg.com/Product/Product.aspx?Item=N82E16827136133
Consider a next gen optical drive. A Blu-ray/HD-DVD combo drive is a good idea, at least Blu-ray. Something like that^.

-Go for a 8600GT as a videocard, they have Purevideo (hardware/software video decoder).

-As for a case. I recommend a larger HTPC case with a screen (if budget allows) that supports full ATX mobo' s. The Zalman HD160(XT) is worth a look. Although I don' t consider myself an expert in HTPC cases.

-As for the Mobo/CPU, I would go for an Intel P35 mobo and something like an Intel Core 2 Duo E6750 CPU.

-RAM->Something reliable like this is good, Corsair XMS2 TWIN2X2048-6400C4

-HDD-> Seagate Barracuda 7200.10 500GB

-Power supply->Corsair CMPSU-620HX 620W

-As for software, I have no idea.

Those are just some ideas....