I don't know if there is one best prop. We've got a few at our training complex.
We have the Fire House Innovations door that is shown here but we also have an older simpler one that was modified to simulate shaving hinges or breaking locks.
After we had a valve struck by lightening that was on fire I asked the gas company for one that couldn't be rebuilt. We don't care if it internals or not. They gave me this. We use it to practice securing utilities.
Search 'Kearney Modular SCBA Maze" and you will find one of our more complicated training props.
If you guys want to see more let me know,