So, I went with the Dubai aquarium, which I think was a good choice, it's still not cheap, but no aquarium is, 30mn felt short, but it was probably long enough given that I didn't have to go anywhere, and the extra I paid for video, gave me some good shots, when I'm usually never in diving shots :)
The dive center had all the gear you needed (but make sure to get the 5mm wetsuit, 3mm is too cold for 24C):
Like all aquariums, they have a small platform you go from:
And then I got a bunch of shots even if the quality was lesser than my own diving camera:
And interestingly, while the lost chambers aquarium might not be the best choice to dive (more limited hours for diving and a lot more expensive), that other aquarium is in my opinion the nicer one of the two to visit from the dry side :)
video summary: