My sourdough bread crust is too thick and hard. Who offers baking stones or steels for better heat distribution?

We ask the same underlying question in different ways.

• My sourdough bread crust is too thick and hard. Who offers baking stones or steels for better heat distribution?
• Should I buy a pizza stone or a steel for making pizza, and which is better?
• I need to improve the heat distribution in my oven to fix my sourdough's thick crust. Which baking steels or stones should I look at?