Well, hmmm, I got some deco training in my NAUI courses, many people know how to read and and understand the tables without going to a PADI merit badge course for it. I understand what he wants and means by limited but possible deco given the depth of the dive and the possibility always of something throwing the best laid plans aside, be prepared on this dive to deal with a short deco is a good idea, that is why I am recommending more than an 80, not so you can stay down longer as that is limited by deco obligations/physics but to be able to deal with an OOA or equipment malfunction, say, of another diver, and still have the ability to catch your safety stop or a few minutes of required deco resulting from some unplanned fiasco.
Now, if you make advance arrangements the ops in the area can arrange single tank "tech" dives where you can run doubles, scooters etc but the typical O dive is a two tank dive done within the recreational limits--but---always be prepared at these depths to handle what ever might come up, even a little deco.
I suggest contacting MBT Divers and see if they can book you a trip, tell them your preferences in boats, tanks, Nitrox etc (fast and little, slow and big etc) and see if they can work you a captain and boat to your liking. I have used the Y Knot and the H2O Below and one other with good success.
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