Thought this might be of use to you. Before buying the Pegasus river pieces, I had no idea what size they were compared to our 1/32 figures. So, here are a few pictures. It's made of a very hard plastic and the pieces lock together. I bought two packs, 12 pieces in all. It's plenty of river for me, though it might be a touch on the narrow side for some. The Barzso pieces are much wider I think, though I don't have any on hand to measure and compare with. So, it really just depends on the type of river you want.
Tomorrow we are adding to our little family. We are welcoming a new kitten to the fold. It should prove to be an interesting day. It's going to be spending it first couple of weeks living in my Toy Soldier room. I'm cleaning it up right now to be a bit more kitten friendly.