I would lean towards finding a good dive operator and talking to them and letting them know you are interested in doing the dives, but you are newly certified. If they are a good dive operator they will either set you up directly with a divemaster or instructor for the dives, and they will keep an eye on you. I just got back from a cruise where I saw both extremes on the dive operators. The operator in Isla Roatan just loaded everyone up on the boat and told us to gear up and suit up. They did not ask to see if anyone was more or less experienced or even newly certified. We were on a shallow dive of no more than 50' but there were still people who were newly certified. In Belize they quickly interviewed everyone about when they were certified, how long they have been diving, how many dives, and what type of dives. They then closely watched everyone as they set-up their gear. The people who exaggerated their experience stuck out like a sore thumb. I had a couple who said they had been diving since the 60's, they did not know how to attach their yoke regs to the tank, when asked if they needed weight, they looked at the divemaster with a weird face, and then they threw in even more of a complication of carrying a camera.
I am not going to say I am super experienced, I only have 35 dives now, and have my buoyancy good, but there is still room for improvement on it. I will go for the PADI master diver rating, but not for any reason other than to keep learning. I will also do the rescue diver course, and oxygen provider course as well. If I do continue on to divemaster or more, it will be just for furthering my education. I do not want the liability of that comes with any of those levels.
I will do get my advanced open water this spring when the water warms up, I have done my reading and pool dives, I now just need to do the open water dives for it. As far as the advanced making me feel more confident; I cannot say it is going to do that for me. I have done most of my diving with instructors or divemasters and have worked out my navigation skills, I have done deep and boat dives, I am now in a drysuit, and will do peak performance buoyancy in the spring.
Brent