I'm wondering what a good flash for the D800 would be. It doesn't necessarily have to be brand new, but I was thinking either the SB-800, 900 or 910. I'm also not looking to break the bank, as my first child was just born. However, I have some old SLR film gear that I either never use or replaced, so I'm going to sell it to afford a good flash. One of my friends did not recommend the 900 because there are apparently some overheating issues with it - he's an event photographer and has had the flash shut down under heavy use. Also, I do currently have an older SB-25 speedlight. It's not an iTTL lens, so I use the flash in "A" mode, but aside from having to manually enter the focal length, ISO and aperture, it works very well with the D800. What would be the advantage of using a flash that is iTTL compatible (if that's the right term for a flash made to work with digital bodies)? Will the camera and flash be in sync with each other, will the flash have a greater range?