I think the laminate pieces look great, and I think flexibility is great for kids. I always try and keep an eye out for pads of craft/card making papers, that are about the right scale for Playmobil wallpaper and such, and are usually pretty cheap.
I had a big painted table as a kid - me and my dad had a fun day where he marked it out and we painted it together. When I decided I wanted water I would steal a towel and put my boats on that