We have all those build-it things in our house too. The "big boy" LEGO are the current favorite but we have Trio and Tinker Toys and Duplo and Mega Blocks and the little kit with tools. So much fun making things. And then destroying them. :)
I see architecture or engineering in their future!
Wow those are fantastic! And I love those toys for Rhian too. Keeps us both pretty busy and having tons of fun.