S.B.
Target or WalMart have pads in the baby sheet area that is 2x4 feetish that feels just like a sheet but has a waterproof backing and lies flat on top of whatever you are trying to protect, it doesn't move and is great. It is not like those horrible plastic, crunchy, make you sweat things! If I can find mine, I will look for the name brand and send you a message.
The mattress saver or mat is made by Priva, it works awesome! I hope you are able to find one.