For the moment, my plan is to use slightly scaled, tinted infestors for small sandworms, and nydus worms for large ones, but I haven't decided on the correct mechanics. Emperor: Battle For Dune is my made inspiration for this map, but I'm also planning to stick closer to the books. It should work out well overall. I've got some ideas for the factions, which I'm pretty confident about, but I plan to get sandworms done first.
EDIT: Decided to start working on harvesters and carryalls. My goal is to have carryalls be automated but destructible, though certainly rebuildable. Can't seem to make it work, though. I set up a trigger to pick all of a player's carryalls when a gather or return order is executed by a harvester, and have idle ones pick it up. I'll probably also filter it so it just grabs the closest one, but atm none respond.
Second, I want harvesters to collect multiple deposits before returning to the base, but the resource system doesn't seem to work that way. I also don't seem to be able to make harvesters buildable.
I'll upload the current version to mediafire soon, since it's a non-functional version, while all the ones I post in the main post here will always be functional.
EDIT2: Now the carryalls pick up my harvesters when the harvester is ordered to go gather, but only when the player does it. Also, the carryall doesn't bother going and unloading the harvester. I've got some ideas, but its coming along.