i would like to program this in linux.
Linux is an operating system, not a programming language.
with an option to use a high-speed camera triggered by
And do something with the picture? Forget it. Just making the camera take a picture is easy enough, with the right camera and right code.
i want to order everything at once
Probably not the best approach. You'll need to experiment with how far you can transmit data underwater, via bluetooth (extremely limited range in air) or wireless. There is not one wireless method. There are many. Each has its pros and cons. Range underwater is going to be less than in air. Count on that. There is a reason most subs are tethered.