That would be a good application for 3d printing. You would need some design software (I use the free version of Fusion 360) or an account with an online design website. Take your measurements. Design what you want. You create an “stl file”. Then the design gets processed in a “slicer” software package that prepares it for the printer. One decent place to get started is makerworld. Many websites will print the item and ship it to you. Or, talk to your friends. You may already know someone with a printer. There are many materials to choose from. For that, I would use ABS or one of the carbon fiber impregnated materials.
Or, make something out of aluminum or steel using common household tools. That’s not terribly difficult.