We are doing a similar update. Originally our shower was tile that leaked after 8 years. So we replaced it. That leaked after 7 years. We had planned to do tile again but at the last minute switched to flexstone/sentrel panels. So very happy we did. I think this shower is going to last alot longer than tile.

Here is a thread on our remodel. Not done yet as we are slow as molasses but so far we are impressed with the ease of installation and the overall look of the product.

https://www.houzz.com/discussions/5918286/flexstone-sentrel-panels-calacatta-white-pictures#n=8

Their product can either go over existing tile or be put on new wall board. You can buy direct from the company to get the taller walls, upgraded niche, corner seat etc. Or you can buy from Home Depot that has a subset of the products and the kits. Home Depot also has lots of reviews so you can see what other people think of it and see their finished showers.

I don't know if I would go with their shower base due to the material. However I think it is plenty rugged enough for shower walls. We went with Swanstone solid surface and strongly considered Onyx but theirs didn't come with the drain hole in the right place while Swanstone's did.