I don't want to sound harsh, but in my opinion the D700 has plenty of buffer for a shot like that. You just need to be more aware of your buffer, and the expected sharpness consistency for the particular shooting situation, and shoot accordingly.
There are some specific situations for which I find the D700 buffer limiting but in most cases, including things like Birds In Flight, I manage. But I do manage my buffer.
Now, if price were no object I would shoot a D4. But if that were the case we would all be shooting Pigs In Flight too, with that huge buffer
When I set my D700 to 'raw only' I get an indication of 17 frames available in the buffer (r17 on a half press). If I add JPG large Fine (for Raw+JPG) it only drops to 15. So I'm not sure that is a game changer either way. I do shoot raw only, but I use Photomechanic for my browsing and front end work. That can make 'raw only' a little easier to integrate into a work flow.
While on the subject of D700 buffers, I mentioned that with my normal setup the best I get is an r17 buffer capacity. Thom Hogan, in his eBook, suggests a higher number that I have never achieved, even with a shooting and custom bank set to factory defaults. I'd be curious to know if my r17 is typical here.