These cards have a max read/write speed of 45MB/s and are UHS-I Class 10 cards for a 10MB/s minimum sustained write speed that will accommodate HD video capture. For more info on SD card specifications and usage type, see my prior post Demystifying SD Cards.
Adorama has a deal on Samsung SD cards, including a 2-pack of 32GB SDHC cards for $34. Also in the deals is a pair of 64GB SDXC cards for $67. Check them all out here at Adorama.
Adorama has another deal on Samsung SDHC and SDXC cards.
Learn more about SD card ratings and types: Demystifying SD Cards