Wow, that's a great boat.
Something to think about though might be a bigger fuel tank. I'm not sure what the consumption rating of the twin 150's is but 120 gallons seems a little lite, at least for long tuna runs.
I've got a 2 stroke 120 and have 82 gallons and wish I had more. Since you're ordering her brand new, now is the best time to go bigger!
If you're planning long offshore trips, the other item you'll want is a fuel flowmeter. Navman, Standard Horizon, Floscan, whatever, just get one.
If you've got plans for any other jewelry, ie. radar, gps, fishfinders, cb's, VHF's, etc., get them to run the wiring and do the mounting if you can. Much easier to do when things are still all torn apart.
Also, as I've noticed from some others that have recently had boats built, push for as early as a delivery as possible because they WILL ALWAYS RUN LATE! I can only imagine, but it must be the worst feeling in the world to have fishing season start without your new boat in hand!
Good luck and I can't wait to see it out on the Blue!