Today I release a version of the Tropics that you can use on a 1/4 region. It has eight different scenes inside (volcanoes, mangrove islands etc), all in three editions with dedicated textures making 24 setups to choose from.
This item will only be available in the Gold edition, which means that it's copiable and that its appearence can be changed by means of a HUD. Moreover, you can remove unnecessary scripts and sitting on any object on the sim will not be blocked in any way.
The new Tropics environment is available here, and it's very attractively priced. You can get a demo to try it before you buy the real one.