Kohler makes a solid shower pan. Go to build.com and research different options and brands.

Grifform makes custom corian shower pans. Expensive, but great for odd shapes spaces.

Is it just the pan you are reolacing ? IMO a much simpler shower stall would be a much better choice . Of course I would need to see the reason for this complicated shape Usually the wall tiles are damageed when removing the shower pan so could end up being a whole new shower . Post pics of the whole space where this shower is please . Post here in a comment.

Kohler shower pan

Your problem will be the custom shape.

It’s an odd shape because of the location. I don’t know how I’d relocate it.

I have similar shape due to location of turning staircase behind the shower and radon vent on back side. We were able to rotate a toilet to enlarge shower but we did keep the small back cut off corner which didn’t allow a standard pan. Also had corner tub and window on same wall. Ceiling heights all 8’ tho. A reputable bathroom contractor should be able to easily build it correctly and water tight shower

Katya are you doing a full remodel or just discovered a failed shower pan?

I discovered a failed shower pan. I’m just hoping to redo shower and tub to save on costs.