Yes, as others have already pointed out, it's much better to have multiple smaller cards, rather than one gigantic one. Don't "put all your eggs in one basket", so to speak. 16GB will hold upwards of 500 RAW files, or 32GB well over 1000. If you shoot JPEGs, you'll get even more shots per card. How much do you need?
A 32GB card is the largest I'll use in my cameras. I have 6 of those. I also have a dozen 16GB. All together, I could take more 10,000 images, if I really wanted to! (I do take 3000, 4000 or even 5000 in a day at some events. It's a lot of post-processing, though.)
Memory cards don't fail very often, so that's not a major worry... though it does occasionally happen. (Out of more than 100 cards I've used over the years... I've only ever had two fail and both of them did so immediately. One was unable to format right from new. The other worked once, then locked up and was inaccessible.)
Buy good cards... they aren't expensive. For example, Sandisk Extreme Pro 32GB SDHC UHS-I are currently selling for $35 for a two-pack, from reputable stores. There are also inexpensive memory card pouches that can attached to a camera strap or larger, more protective cases that hold 8 to 12 cards.
Also be sure to write your name and email or phone # on each card with a permanent marker. On another forum we had someone post who had found a memory card laying on the ground, took it home and saw that there were some 500 wedding photos on it! They posted a couple of the images and someone on the forum recognized the church. The person called the church and asked about weddings from the date the images were taken. Long story short, they found the photographer who had lost the card and she was EXTREMELY happy to get it back, since the wedding shots were irreplaceable! (She had used multiple cards, tho, so it wasn't a total loss if she'd never gotten the card back.)
Not everyone is so nice as to make all that effort to return a memory card. Or it may be that they wouldn't be able to identify you from the cards contents. So make it easy for them and write your name and contact info on your cards! You may never need it... but if you ever do, you'll be glad you did!
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Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7DII (x2), 7D(x2) some other cameras, various lenses & accessories
FLICKR & ZENFOLIO
