I have something similar to the first blocks that i used to support the boards for a raised bed. But I have never seen the ones that hold a 4"x4". (Saving the pix).
Just want to make sure you noticed that the links will take you directly to the Menards webpage for those blocks. If you don't have a Menards, you could probably print out that page and show it to your local building supplier so they can see exactly what you are looking for.