Best module where you create a block and select a node from drop-down to render?
The Nodes In Block module seems to give you the desired outcome - albeit a different workflow to what you described. Here is an excerpt about it from the module's project page:


  ... makes it possible to add nodes into a block. A number of configurable blocks are generated which you can assign to a region. Visibility settings of this block are automatically set to 'Show on only the listed pages'. On the node content form, you define the weight and visibility per node thus making it easier for content administration as all your content is now in the same place. With this module, you don't have to explain your customers how blocks work but is still able to decide on which pages content must be rendered.