I have a Canon EOS 7D and I want to start using it for cockpit shots, and to make them perfectly exposed I want to use an external directional flash that would mount on the top of the camera. The plan is to focus on the outside, while aiming the flash at the overhead panel to bounce back onto the rest of the cockpit for a perfectly exposed shot, a method that I learned about in other forum topics that is supposedly the best way to do it.
How do I determine what flash would better suit this need though? Would something like the fairly inexpensive Speedlite 270EX suffice, or would I need something like this one?
Thanks in advance.