well i have used the sandisk extreme pro on a 7d. 90mb/s write speed. 32gb is the only way to go. a bit pricey but well worth it. won't run out of space...unless your shooting a 6 hour concert, i ran out on the last band shooting at full 1080 (with lots of clips here and there, not straight through each band). so you won't be disappointed. thats my recommendation.
Check Out KoopA Clothing