Despite regular practice, I still have a problem of grouping to the right of center.
Im likely having grip and/or trigger control issues.
Ive been experimenting with the various recommended cures, but not consistent.
Dont want to keep reinforcing bad habits, so would like some instruction from an effective, quality teacher.
Im guessing there are hundreds of instructors around Arizona.
Who is considered the best?

Independence Training.

Back in the day (circa 1988) I went to Gunsite up in Paulden .

+1

Glen and his team are great at what they do.

Independence Training.  Gunsite is very good too.

Never been there, but I’ve heard good things about Haley Strategic as well.

In your search for firearms training ensure you have an objective or goal you want to attain and choose a firearms class that provides you the basics and techniques on how to analyze your performance. I’ve been to a lot of schools both self-funded and at government expense and they all involve sending thousands of rounds down range but miss the mark on the proper techniques of marksmanship. Once you obtain an acceptable skill set then it’s time to seek gunfighting skills. Lots of courses out their jump right into their version of gunfighting and survival skills; you end up trying to play catch-up and develop bad habits or continue to validate bad habits through repetition. You indicate you’ve tried several techniques and yet you still produce the same results on target.

Next time you go to the range focus on the three elements below and analyze each behavior and how they impact your performance.

1. Mental—what’s your goal you want to attain for that practice day. Is your mindset ready for constructive practice are your expectations obtainable and within your current skill set to obtain your expected goals for that training day. While operating the firearm are you focus at the tasks at hand before moving on to another task. How to you identify cognitive thought and subconscious ability while performing your gun handing skills. Are you focusing on just one element or are you letting yourself just perform in real time and playing out your performance and analyzing your results.

2. Physical performance—while operating the firearm what physical feedback is occurring and how can you improve. What does it feel like and what physical inputs or behavior are you deploying to improve. Are you focusing on just physical ability and not focusing on what you feel?

3. Visual input—What are you seeing and how are you seeing your sights? Are you just using one sight reference or getting caught up in the 3 focal planes of the sight picture? How do you recognize sight focus, target focus, and finally the 3 focal plane sight picture to achieve your accuracy. Distance to target, difficulty of the shot and the terrain are going to dictate those uses of the proper sight picture.

Theses are just a few considerations on what to look for while searching for that school that will offer you what you want to learn and how to deploy your firearm when needed to save your life and others or just to plan have fun enjoying your 2nd Amendment rights in our free state of Arizona!

Good luck and I would recommend Travis Haley, Pat McNamara, Bruce Gray; they’ll aid in getting you to develop the skills you desire.

Thanks for all the great advice.
However, before I spend 3 - 5 days and $thousands on an immersive course; I want to get my grip and trigger control straightened out.
No sense reinforcing bad habits.
Thinking more along the lines of a few one-on-one lessons with an effective teacher.
Once I get that straightened out; I'd love to do something like Gunsight or Independence!

Independence full day classes are a few hundred bucks. The instructor to student ratio is very low. Don’t know where you’re seeing multiple days or thousands of dollars...

Are you left handed?

There are plenty of instructors out there. Determining who is best is moot.
What you need is someone knowledgeable enough to spot & correct your errors.

Have you tried self-filming and playing the footage back to review?

For individual private training - Hammer Down

For group classes - DCS

Gator Farm Tactical
Has vendorship for Pima County Parks and Rec.  All instructors are Military or Cops with gunfight experience.
Associated with Mas Ayoob massadayoob.com
gatorfarmtactical.com

Independence Training

Independence Training also has some very affordable private training, if that is what you're looking for.
https://www.independencetraining.com/training/personal-training/

I've taken 4 of Haley Strategic's handgun courses.

I'd highly recommend his D3 class for what you're asking.