One method that I see working:
Add a new JPG Photo mode that saves photos to exactly 4k frame size. Then, use burst firing mode to see how far we can push the buffer.
If this doesn't work, create a photo mode with the highest available burst firing mode possible without exceeding buffer.
We could also code today and plan for tomorrow. Go ahead and write code based on the fact that UDMA 7 1666x speed cards will be available within a year that can provide this threshold. Or, in the meantime someone may figure out the CF to SSD converter process.
Either way, finding a solution to provide the menu options should be our first focus & then worry about buffers and such thereafter.
I only have a Canon 50D out of my lineup that can potentially handle this, so I'll play around this next week and see what I find.