<p>The 6D won't take CF cards it uses SD so keep that in mind. Like others said equipment wise extra cards is the main thing you'd need. Some people like having large cards to avoid switching, I prefer having a ton of smaller cards so that if (knock on wood) one ever craps out on me I lose the least amount of images I can.<br>
Edit: The best solution to that would be the 5D Mark iii and using a CF and SD card simultaneously.</p>