My server closet was a mess. I kept justifying it by saying I didn’t need to waste money on proper rack equipment. Finally cracked and upgraded to a 15u rack and got some 3D printed rack housing for some of my non-rack equipment. Everything looks so clean now. Vanity project? Yes. Expensive? Yes. Am I happy with it? Yes. Do I wish I did it five years ago? Yes.
Do it. Go a little bigger than you need. Airflow. Expansion. Whatever. I probably could have made an 8u work but I’m happy with a 15u.