Interesting one this....I spent a season playing county cricket so I do know few drills that could be employed.
For general fitness and reactions I'd have to suggest squash and then tennis or badminton. Throwing a golf or tennis ball against a wall can help also. Oh yeah and the idea is to catch the rebounds!
Main thing is though do something that you enjoy and that can be part of your lifestyle. I don't think that anything will teach you how to handle an aeroplane other than actually flying it. Having said that an SAA training captain I knew said there was a quite a marked difference in handling ability between those that played sports (or drove fast cars) and those that lived sedentry lifestyles (and drove like old women).