Replacing fiberglass tub/shower with shower

[fstgeorge]

I am trying to find a replacement shower insert that is not in one piece to replace present fiberglass tub/shower. Standard 60 inches. I would like to have the new type glass doors rather than track doors. If only track doors are available, I can live with that. I would like to know where I can get a replacement and any other suggestions you might have.