I'm not sure what you mean by props, do you mean to say Special Bricks like Trees, Walls, and Roadways?
There are no model packs that I know of, though you should look around for individual bricks in the Add-Ons section.
If you want to make your own models, use either MilkShape or QUARK with the Torque Engine importer/exporter plugins. You will also need to learn some basic C script or piece the code together from the .cs files in your Blockland directory.