I am not an expert by any means, but like yourself I went from a D300 and D300s to a D800 and found the transition very easy. I just had to be careful of my technique was all, cos it was easy to get soft pics with so many pixels. My wife has the 70-200 2.8 and I was going to get the same until Nikon just brought out a new 70-200 f/4G which has an updated VR system which is supposed to be truly amazing and works well, this lens is also cheaper and lighter, but going by the reviews I have read, produces results exactly the same as the 2.8. Yes one loses a stop, but it appears to be a lens that should be considered strongly, especially with its upgrades and price! As for cards the cards suggested work really well and when shooting in RAW each file can be high as 41MG size, so speed is of prime importance. I am sure you wont have any problems using this camera on the fly at all.
You will truly love whichever model 800 you get, the results are astounding.
Good luck and let us know how you get on when you get back please