What memory card shot I buy for canon 1400is?

I was thinking SanDisk Extreme 30MB/s SDHC Flash Memory Card - 16 GB. Will this card work well ? I want to use it also for my Rebel XS DSRL. Then I was reading about recording video might require a less class and more class is not always better ? I have the canon powershot 1400is (IXUS130) and it records in 720p. FYI - I have an imac intel with leopard.