Sandisk Extreme UHS-1 SD cards are brilliant all rounders - speed and reliability, just depends how much you wanna hold...
32GB will give you over 2.5k pics in jpeg fine quality.
As for data corruption - just backup your pictures after every shoot if possible, or as often as you can. Generally speaking, corruption is more likely to occur between card swaps etc then say when you're using the camera itself (though don't take that as it can never happen).
Lenses - 18-55 'kit' lens is a very good lens to start with, and as you go down the road, you'll come to use it more often than you might imagine.
If you're not buying it as a kit lens, then depends on your budget.... 18-105mm is a good 'walk about' lens, and a 18-200mm or 18-300 is a very good lens if you're planning on rarely swapping lenses.
Once you get used to the camera, you'll be looking at a prime, 35mm or 50mm f/1.8G are both amazing lenses (though the 50mm has the slight edge in IQ I'd say).
Bags - so many to chose from, but Lowepro always comes out on the top of the lists. Again, depends on budget, but spend a little on it - after all it's what is going to keep your kit safe
Battery - see how you go. I've managed to survive on a single charge doing >700 shots and using a SB-400 flash.
But always keep an eye out, as a good bargain buy will never let you down.
