I like mine. It's from frongate. It's a corner seat, plenty big and comfy to sit on. We've only had it a year. I read that every so often you should take it outside and powerwash it, but we haven't done that yet. Be sure whatever you buy has adjustable feet because your shower floor is sloped and you will need to fiddle with the feet to make it follow the slope.

https://www.frontgate.com/resort-teak-collection/517731?searchTerm=teak+corner+shower+bench

For a much smaller shower we got one online from HD. It's more like a shelf to put things on because it's pretty small, but a skinny person could sit on it.

I like Aquateak brand. They have a large variety of shower benches and other teak furniture and products. Their customer service is excellent also. https://aquateak.com