You can get glass ones I think can't you?
You never cover a paella with a lid. All the Spaniards I know (my other half is Spanish and we spend a lot of time in Valencia) cover the pan with a slightly damp dish cloth.
I think stonewares are good. I'm using le creuset now.
I highly recommend the ProCooks range of frying pans.
Yeah I dont go near it, bought some ceramic pans earlier this year love them. Good film too reminded me a bit of The Insider