A saucer shape inverted so that the bulge of the saucer is pointed downward during reentry, imagine a frisbee upside down.

What you've described is pretty close to the heat shields used on the old Mercury, Gemini, and Apollo capsules. They all had blunt heat shields, similar in some ways to an inverted Frisbee.

A jacket of oil or water keeps the metal from melting and a vacuum layer and other insulation insulates the crew area.

The idea of using water to remove excess heat isn't new. I remember attending some briefings back in the late 1980s where a speaker discussed just such an idea. The vehicle he was proposing looked very similar to what later became the DC-X.

The light wide diameter slows the descent until the saucer flips over at some point and uses the air foil effect like a frisbee or a parachute is deployed while it lands inverted.

This part might not be such a good idea. First of all, the flipping over part could be pretty violent. Second, don't Frisbees depend upon the spinning action for some of their lift? If so, then you'd want to put in a despun platform for the crew. That would add a lot of weight and complexity, as well as new failure modes.

It seems to me that a blunt heat shield is a well proven technology, as are parachutes and parafoils. While I don't know of any heat shields that have used water, it seems like a good idea to test. The Russians are testing an inflatable heat shield and the earliest Chinese recoverable satellites reportedly used wooden heat shields (I kid you not).