Looking for new shower pan, need advice on materials, please

I am looking around at shower receptors (have already decided not to have tile bottom, will have tile walls) and don't really understand the difference between all the different materials (aside from cost). I know what solid-surface is and the advantages, but it is very expensive, of course. What I don't understand is about cast iron or acrylic (I thought solid surface was acrylic, but there are cheaper ones that don't seem to be like a standard solid-surface product?) or regular fiber glass or that sterling vikrell, etc. If anyone could please help me out that would be great. I guess just a run-down on what the types availble are and what advantages/disadvantages they have. I have looked around for this on the internet fairly extensively and not found anything. TIA!

ETA: Oh, and another question... I am looking at shower doors, too. Have had a kind recommended to me that does not screw in to the wall but has some kind of compression fitting installation. Would like to hear opinions on these. Seems like a bad idea to me, but the husband thinks it sounds fine.