I have a couple questions. First one starting with I have a Nikon D70 and I am thinking I should get a flash unit for it. What should I look for? Should I go for a 600 or 800? Will it make much of a difference? How much should I expect to pay? Also my other question is on my D70 in the screen where it says how many shots I have, it says "r09" when I push the shutter button down part way. It still takes pictures fine and everything, but I don't remember it always doing this. Does anyone know anything about this? Thanks!