You need to be comfortable so the divng is fun, With your size, I am going to go with the majority and tell you a BP/W setup is probably best for you. Regulators are a personal choice, and I would recommend an over balanced as a whole they do breathe easier at depth, now that said, most manufacturers make at least one over balanced regulator. With exceedingly powerful legs, I agree that a split fin would not be your best choice. In a blade, I tend to like short and wide, due to the fact that I frogkick just about all the time, but once again, my choice, my preference, a lot of shops will let you try before you buy, so try a bunch of different fins, Force, Jet, I haven't tried the new ScubaPro Novas yet, but everyone I know who has is really impressed. Computer...I would only recommend that is Nitrox compatible, user changable batteries, and is easy to read underwater. i love my Suunto Cobra, and D4, but as a certified Aqualung technician, I can change the batteries on my own, so they are not the most diver maintainable ones. You have a lot of time to figure out what works best for you, and for open water class... you really only need mask, snorkel and fins and boots. Though with your size, I would recommend finding or having a custom built wetsuit for the open water dives as most rentals aren't available to someone your size.