Can anyone recommend a waterproof bed liner pad?

p.s. They offer two versions. One basically covers the top of the mattress and the other goes all the way down the sides and ends.

Yes! I'm not sure where your at - I bought mine at Sleep Train, it's a mattress store. I'm sorry but I don't know the brand name but you could probably call the mattress store. Anyhoo - I have used these for years. My son is 23 and severly disabled. When he wets the bed he manages to soak every sheet, blanket, comforter and sometimes even the pillows get wet. The mattress is bone dry. But the real beauty in these pads as they aren't a pad at all really. They are terry cloth on one side and gortext on the other. They don't make a single annoying crinkle sound when you move and best yet - you don't get hot and sweaty from a traditional plastic liner. They are a little spendy but so worth it. I have bought two for every bed I own(ed) for the last ten years - eight in all. Never a fail, never disappointed.