How to select BLDC motor for high torque applications
As a motor designer, I am going to give you a dimensional approach to selecting a motor. Torque is proportional to the rotor radius squared. Torque is linearly proportional to length.
\begin{equation}
\tau \propto r^2l
\end{equation}
What does this mean??
It means that you will want a motor that looks more like a pancake than a hotdog. I suggest you look at axial flux motors (YASA, MAGNAX are examples of companies that make these motors).