Cutting to the chase: Swanstone! For the shower pan and walls of shower. High quality, lovely appearance and low maintenance. We originally did tiled shower walls and shower floor but had to replace the shower floor with a pan (and chose Swanstone) within 6 years due to water leaking into the basement.
Google these terms and read the AI summary: “curbless shower in former tub alcove”. Lots of helpful information there.
Longer version: Here is our story of gutting our small, long bathroom and replacing the tub with a shower.
We have only one bathroom in our small 1960s ranch house. My husband had a hip replacement scheduled for Jan. 2017, so in 2016 we decided to replace our tub/shower combo that had a glass sliding door with a curbless shower and shower curtain. This would be safer for him post-surgery, but also for both of us as we age.
Additionally, the toilet was gradually sinking into the floor, like the leaning tower of Pisa.
There must have been a plumbing leak at some point. There was no option but to gut the bathroom.
We hired an experienced contractor recommended to us by a friend who is an interior designer. She gave us a few simple tips but urged us to figure the rest out on our own to keep costs down, rather than hiring her.
We chose all the materials– tiles for the bathroom and shower floor and walls, comfort height toilet, wall cabinet over toilet, single sink unit, tall linen closet. All our towel bars are securely attached grab bars (Delta). None of our materials came from big box stores. All were good quality. This was going to be expensive, and we never wanted to have to redo it.
The contractor had never made a small curbless shower floor in the footprint of a tub, but we’d seen a photo of one online, so it seemed doable, and he gamely agreed to give it a go. The photo showed a tiled shower floor with a central drain. There was a shower curtain for unobstructed entry.
The contractor suggested instead a sloped floor with a linear drain along the back wall. He used Kerdi membrane but poured a cement floor instead of using a Kerdi pan under the tiles. The floor joists were not cut down. He thought that best, but in retrospect this was probably the critical error. There was not enough depth to install a shower floor at the necessary angle for adequate drainage.
From the start, water pooled while we showered. It didn’t flood out onto the rest of the bathroom floor, but it was like showering in a puddle. The slope of the shower floor was insufficient. The contractor had his tile guy relay the tiles. That was a little better but it still didn’t drain very well. We just didn’t see an option for how to fix it at that point. And we had spent nearly $23K.
So we squeegeed the shower floor and toweled it dry after every shower and figured that was that. An imperfect result, but a safe enough shower for aging in place.
Nope! Six years later, we started getting water leaking into the basement from the shower, and shower floor tiles came loose. We hired a local contractor (not the same guy) to evaluate and redo. Turns out the cement under the tiles had crumbled due to not being thick enough (because joists had not been trimmed down.) And the leakage had happened not through the crumbled floor but from grout at the edges of the tiled floor.
We debated for a long time what to do (decision paralysis!), but finally decided to have a shower pan installed. The shower entry would not be curbless, but it was still low, and drainage would not be an issue. Thankfully we had enough of the wall tiles left over from the first job that the walls could be retiled near the floor in such a way that it didn’t look like a redo. The color Swanstone pan we chose (Ice) was a good match for the color and pattern of the wall tiles.
The shower floor redo cost us over 10K– most of it was the cost of labor.
We love the Swanstone shower pan– it is attractive, grippy and comfortable under our feet. No risk of slipping. It cleans easily. Yes, it costs more, but it is sturdier than some shower pans and should never crack (which can happen with cheap shower pans).
We really, really don’t want to ever have to do it over! 
I use these strong shower curtain magnets to make sure the shower liner stays inside the pan, and the outer curtain stays outside the pan. https://www.amazon.com/dp/B0C72LT628?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
We have to clean the grout on our tiled shower walls. If I could do it over, I would choose Swanstone for the walls also.