While browsing SanDisk’s site, I noticed the Extreme Pro SDHC and SDXC UHS-I card is now available in a 2TB capacity, expanding the existing range, which previously topped out at 1TB.
The primary alternative I'd be looking at is the Crucial X10 Pro, which offers double the speed of the Sandisk Extreme - 2100MB/s reads and 2000MB/s writes - and performed excellently in our testing.