Lahaina Divers does a 4-tank package. Sunday would be a morning 2-tank trip to Lanai with an afternoon charter to a West Maui site.
Nobody will guarantee you that you will go to the Backwall on any given day. If conditions are bad, they simply will go inside of the crater instead. If you want a better chance of a Backwall dive, Ed Robinson's runs an Adventure charter for more advanced divers on Sundays and usually goes to the Backwall for a first dive.
Unfortunately, it's impossible to predict whether you'll want a wide angle or macro lens....sometimes there are amazing things out in the blue water to photograph and other times you'll find many tiny things on the wall. Personally, I think you're more likely to need the macro lens than wide angle, but of course that'll be the day that 2 Mantas come swimming by and stick around for 5 minutes.
If you go with Ed Robinson's, you'll only be doing a 2-tank morning charter out of Kihei with no afternoon possibilities. However, you could book an afternoon charter with Maui Dive Shop for their 2-tank Manta trip at 1:00. They depart out of Maalaea Harbor, a 15 minute drive from the Kihei Boat Ramp. A friend of mine works for Maui Dive Shop and says they see Mantas pretty regularly on this charter, so it might be a good option for you.
