I checked my cards - 30MB/s, equivalent of U1 speed - so consistent with what is recommended above. Those are still below the knee in the price curve.
Be careful with the Sandisk's "Capacity Chart". The fine print says based on 3.5MB file. I just finished downloading a shoot and my files are about 25MB each. Sandisk says 4,000 pix on a 32GB card -
your camera manufacturer says as few as 858. I'd says that's a minimum size if you're shooting RAW format.
I've never lost, damaged, etc. a single card, so I don't subscribe to the "buy a whole lot of small card" theory. Following that logic, I should buy a case of the 256MB cards I still have from my first digital camera and change cards every 10 shots). Mine are 16-64GB, the best price point based on when I bought them.