A mirror cell is really pretty simple for a mirror like that one. Wandering through the various telescope making websites will show a bunch of different designs. You may also want to download PLOP.EXE to figure out where you really want to put the mounting points for the mirror.
As far as details, you need to support the mirror at 3 points from falling out the back of the tube and at 3 points to keep it in the center of the tube and those last 3 points usually have a lip on them to prevent the glass from falling out of the front of the tube. Additions include fans to cool the mirror to ambient quickly and holes to allow for the same.