I got a 2 pack of lexar 32gb cards with a usb 3.0 reader. I'll see if I can find the link from my amazon purchases. The cards are blue/black with white text, and speed is listed at 633x. The speed is enough for 4K or 1080/120p (should handle other modes, but those are the ones I use). I could've gotten the 64gb card for around the same price, but I went with this pack because the reader was included. USB 3.0 is so much faster, I'm really glad I got it, but obviously you need a computer that supports it as well.
