The SanDisk Extreme Pro at 90MB/sec will give you the stellar performance, at a cost. The D800 can take advantage of this card's performance. However, if you aren't going to be snapping away at high speed the SanDisk Extreme at 60MB/sec is quite acceptable and is approximately 1/2 the cost per GB. For example:
SanDisk Extreme Pro 16GB = $101 at Newegg
SanDisk Extreme 32GB = $95 at Newegg
I use the 32GB Extreme cards with my D800E. The write performance is a non-issue as my technique with this camera includes using the 3 second shutter delay from a tripod. Taking 1.0 seconds/photo to write vs 0.8 seconds/photo really doesn't make a difference to me. Compressed NEF 14-bit are around 40MB. Mine seem to range from 30 to 55 MiB in size.
I went and picked a recent folder of NEFs and it was 4075 MB with 103 files which yields an average of 39.6 MB/NEF. Therefore, a 32GB card will give you around 800 shots.