In general, an external building profile is the most commonly used as it is the more widely available and simple in design compared to other profiles. It would be beneficial to have an external profile that is able to be converted into an internal profile so that if the need for an internal profile arises in the project you do not need to buy another tool.
Although the profile with stay bars may seem the best option due to its ability to be used from the beginning, it is a lot more complicated to set up, more expensive, and generally a spirit level is still needed every few courses to check the accuracy of the wall.
