A master diver I know recommended Scuba Shack (he spent time in Maui and worked/trained with Charley Neal).
We listened to his advice and were very pleased with our captain and her dive masters.
It is a smaller boat, but it has a toilet and fresh water shower. They bring along drinks and energy bars for mid-trip (They also provide all equipment if needed).
You leave very early from boat ramp in Kihei, to get ahead of the HUGE boats and all the people.
www.scubashack.com
Have fun I am sooo jealous.