For someone looking for the same thing... but for ATX and Micro ATX boards, PerformancePCs.com sells Lian Li motherboard trays. http://www.performance-pcs.com/catalog/ ... 10_750_753
That was the odd thing to me: Lian Li & others make motherboard trays for MicroATX and larger, but it seems like nobody made them for MiniITX. I decided to fill that gap
(especially since I wanted to build an ITX system myself.)
In other news, I also have PicoITX motherboard trays that fit the three most popular Via boards. They also attach to what you're building using 10-32 screws and hold a laptop hard drive, mounted in a frame underneath the board. A pic:
How much extra would it cost to make the rest of the case?
A MiniITX case? I'm not sure, and I think it depends on what you were looking for. Right now, I'm having components for the case machined using Ponoko, a rapid prototyping/fabricating company that allows you to send your own designs in. The cost varies wildly, depending on what materials you use and the specifics of your design. And, I decided to go the fabrication route; I'm sure that someone with more time on their hands could do what Ponoko is doing for far less money.