There are many fine dive establishments here, Jack's does a good job and one of the better Manta briefings.
I have to agree with the other poster that you do not need to do a 3 tank advanced to experience diving at its best. Other operators do three tank local dives if that is what your looking for. The local dives offer depth and a variety of topography. All in all I would suggest using a company that dives 80's and allows bottom times in excess of 60-70 minutes(Not all operations are receptive to this practice.) Because really...it's about bottom time, so a reef dive to a max of 50 feet will allow you to experience more, than a deep dive for 20 minutes.
The other decision is a six-pack boat vice a cattle boat, both have their pro's and con's
such as a more personal experience on a six pack, but more comfort features on a bigger boat.
All in all, you can always try different operators to see which one fits your style of diving the best. a couple I like are Dive Makai(but no longer in business)
, Wanna Dive Kona, and Kona Diving Company.
Good luck, have a great time here.
Also Splashers Grill on Ali'i has great burgers!
Brian