The Sandisk 64GB 120MB/s Extreme Compact Flash Cards are well-regarded in the photographic community for their quality, durability and speed.
Shock and vibration resistant and operable in extreme temperatures, these cards won't let you down when you need them most and your data will be much more secure against loss or corruption when compared to cheaper cards.
What's more the cards' high write-speed (85MB/sec) better optimises your camera for burst shooting, recording HD video and for using RAW files.