Yes the A4000 cases are much larger than the A1200 cases.
The A1200 models we currently sell are only 17 inches high but have plenty of room.
you could easily put both the scandoubler, a bvision, a mediator SX and our video switch in our current A1200 cases no problems.
I know people who have.
Since you have both the Bvision and a scan magic you might be interested in one of my Video switchers. It is a completely internal electronics switcher. with 350Mhz of bandwidth assures you no distortion or ringing of your video. All you do to switch video modes is a simple software command or a lighted push button on the case to switch the video. Yes I know it is not listed on the site. I have several thousand items that have to be put up there.
will post soon.
The only A1200 setup that needs a larger case is the ZIV users because the zorro slot standard requires almost 14 inches from back to front for the cards that will get blocked by the drive bays on our current A1200 cases.
The ZIV will be acomodated by our newer A4000/A3000 cases
The Video switch is $80 US