If I wanted to make a CF purchase right now, considering I currently onlyhave a 40D, what is the best card I can get? I know I am able to use the Extreme III, but if I wanted to get an Extreme IV for compatibility with future bodies will it work with my 40D? I am not worried about maxing that cards capabilities right now, but want to make sure it is at least compatible.
On a related note, will even a 1D Mark III really fully utilize the speed available on a UDMA card at 45MB/s, or is 30ish really all I would need even for that smokin' hot body?