John, thank you very much for providing that new link.
Sid, I've never heard of a thrust augmenter, but it makes sense if it works in the same manner as a carburetor venturi.
The main problem with "doughnut" platforms and skirts is that they're primarily used only for small machines, such as might hold one person and be powered by something like a leaf-blower or lawnmower engine. "Steering" is achieved by the pilot shifting his weight to allow air escape from the opposite side. In this case, the machine is far too small to hold a gerbil, let alone a human. The only ways that I can see to control it, therefore, if no thrust motor is provided, are to either install rudders in place of part of the skirt or to build a weighted payload onto some sort of cross-table (such as is used in a multi-axis plotter) to move it around. Since the rudders also would require servos, either approach would add a horrendous amount of weight.