Yikes!!!
Can't wait to read your review. I would be concerned with a couple of things, this based on my experience with the 200mm f4 macro.
First, it's a b*tch to handle. The length of the port makes an ungainly unit. Move your strobes forward and all your system wants to do is fall forward.
Second, it's a slower lens. Forget AF. Everyone says that, but I used AF on the 200 because I couldn't get the focus gear lined up right. It's not easy though, but neither is manual focus. Any movement requires a refocus. The tried and true techique, supposedly, is the set your focus and move yourself. Again, easier said than done. Any minute movement of you or the subject makes focus difficult. DOF is pretty slim.
Third, where are all the folks who insisted the 60mm was the way (vs. the 105) to go because with digital because it allowed you get closer? With an equivalent 105-270mm you can get yourself pretty far away. Beyond strobe range.
I found the 200mm great for very small skittish creatures and eyeballs. Works really well on land though.
Is the tripod collar detachable? Ikelite couldn't provide a port for the 200mm because the tripod collar will not come off the 200mm. No problems with the Aquatica.