Oh! You just want to build lots but not really play. There's a Lot of them on the Exchange. I wish I had a list... That world is small, though. The Medium maps are 1024x1024. Small is 512x512 and since you have IP you'll probably want to add dive lots? That map probably doesn't have any room because it was made before the IP expansion.
RV and SSV will be fun. I know of a modified SSV but that's the large map. It's been flattened and I hear many like it.
I do have a few empty but and are base game but they also won't have much room for the IP dive lots (medium worlds). :(