I would be concerned that the expert you hire to build it is also the man you hire to clean it. He's incentivized to make something that may look beautiful but need constant maintenance. If you learn a bit about the different hardware/practices from reviews, tests, and youtube videos you will know a bit to give him stipulations to make sure it's low maintenance.
Make sure it's quiet. If people are over to inspect structure and you think you might get a water bed sometime while still in the home, have them check that spot too. See if there is a concern for humidity with 150 gal, depending on the room it's in. Also, most of the "furniture" that the tanks sits on top of with the equipment below is really ugly. That's the only thing that tends to look bad about a lot of tanks that gets missed.