So, I've got a mini-PC installed on the ceiling for the first prototype. This is a Zotac box, with an Intel D525 processor. Its performance for the computer vision software is good (Sometimes 17 frames/sec). The camera is a Logitech C525, which has a very nice articulated base, and can be easily adjusted to point the correct direction.
Unfortunately, there's no room for the projector on the ceiling. All projectors I found need at lease 3 meters from the projection screen, and I have less than 2 m from the ceiling to the table surface. There are some low-distance projectors out there, but they are expensive. I'll try to put the projector at another position, and then fix the image distortion via software or via the projector.
Wife didn't get very much happy, so I'm already planning a lamp or something else to cover it. :)