I have stuff from all over, cavy coture, pimp my piggy palace and from Polly and all are equally popular, Polly's stuff is cheaper. I think one of the other 2 places ives to rescues too. My lot DO pee and poop in theirs (Kimberley can you ask yours to teach mine how to stop doing it please!). I tend to wash them every week too and because they are fleece they dry really fast.
One thing I will say is that not all my pigs like cosy's but all do like beds.
And the crash pads are brilliant, but they do trample on them and kind of spoil the point, so I use twisty ties to attach them to the top of the cage so they can't trample and can only sleep inside them properly.
Getting a spare pad or 2 for them is a good idea as then you can wash the pad not the bed.
OH and one last thing - with the beds and crash pads you can fit heat pads in them which is perfect for the winter months.