Well...given that I only dive a couple times a year on cruises I haven't really had the opportunity or desire to put much time into doing much more than basic stuff. I'm happy keeping things simple.Given the above details, I would say don't pursue nitrox. Rather, I would recommend you learn to become a competent, independent diver. Get your own computer and learn to use it to execute your own dives. Until you can dive independently without having your life dependent upon a dive professional (DM/Guide), you really shouldn't be taking on nitrox in my opinion.
However my wife just inherited her parent's house in central Florida. We expect we will be spending the winters there starting next year. The community it's in has a dive club and frequent (monthly) meetings and dives. I'll look into it next time I'm down there.
And...I started looking at computers so there's that. Any suggestions for a basic, beginner comp?