"perception is all there is"
A book to live ones life by by Tom Peters.
I get it...the internet sucks because people don't type complete thoughts or ask the right questions. Just keep in mind that all a person can really do here is throw out things that people, like myself, have learned over the the years. I can't make your decision for a pot for you, but I can throw an idea your way. It is up to you to do the research and decide what is best for the tree not you. In a thread last week or so I spent many days posting pictures from four books on the proper use of a tall root stand. I am not going to do that for every poster here, it is time consuming and I got pots to buy and stands to build. I hope you are doing the research and looking at trees that look like yours and have seen that indeed many are planted in shallow round pots to accentuate the tall nature of the tree you seek.
A place like this is made up of many people with different levels of experience. many will just agree with everything , some will challenge but not sure why they do, some have the knowledge but are terrible about connecting with people and a few...few will have the experience, the writing skills and the confidence to tell someone what the norms are as a whole. That's what I do. I look at thousands of trees annualy in exhibits around Cailfornia. So when Al says your tree would look best in a thinner round pot, I would look to find out if this guy is right or just out there. Trust me I'm not out there, that you can take to the bank.
Now that you know, what have you found out in your brief research, post a picture or two to show this. Make this place a classroom. You can be a teacher too.