Which SD card will work best with this camera? How long will an SD card last?
Ok, let me give you the real dope about these cards - first: full disclosure - I work in a camera store and I would love to sell you the highest speed top name-brand SD cards and make a hefty commission on the sale (the mark up on the Sony SD Ultraspeed cards is 90% - got it!)
1. If you are shooting videos or continuous burst mode, yes, you need the highest speed cards - otherwise, if you shot only single shots, any speed will do. I shoot with Class 6 to Class 10 Promaster cards on my D7100 (and rented D800 for events) all the time as I don't do videos and I don't do continuous burst. Promaster is our house brand and I get them practically for free!
2. SD cards DO NOT wear out - they will last FOREVER - But you MUST format them regularly. SD (and CF) cards are NOT archive media - they are not meant to retain your images for forever - so as soon as you get a chance, unload your images to your computer or the Cloud when you have unloaded the images format your card and use them again, and again and again - formatting each time you got all your photos out of it. They like to be formated and you must format them regularly for them to be reliable
3. Always ALWAYS format the cards on the camera you are using it in - DO NOT format in a computer or another camera. What formatting does it rebuilds the index and directory tracks - and it's the index and directory information that lets the camera know where the next blank space is available to write new images on and let card readers know where to retrieve the images. When the index or directory track is corrupted aka screwed up , you will get a read or write error. We have customers coming in the shop crying because they have lost images - only to find out that they have never formatted the card ever since they got the camera 5 years ago and have 2000+ pictures in it (didn't know how or that they are suppose to take the images off!) We charge $50 for image recovery - takes a couple hours but usually we can recover 99% of the pictures.
So, there you have it - hope this helps!