crankset compatability
 

My BB is a threaded 68 mm English with a Megaexo FSA crank. I want to change it to a Dura ace and have a couple questions:

1. I'll probably go with a DA 9000, but will past models (7800, 7900) also work?
2. Is it necessary to change the BB bearing cup since I assume both are 24 mm spindles? If so, stick with DA cup or upgrade to a fancier ceramic type?

Tell us about the rest of the drivetrain (cassette, rear derailler, etc.)

The present RD/FD are Dura ace 6800 with a 11-28 cassette on a 2008 Cervelo R3. I am considering up grading to either Ultegra Di2 or even 9070 over the winter. Thanks for any help/suggestions!