Actually it shouldn't be strictly Babylonian as you are developing the lost world but better to stick to one architecture style. So is often useful to have some culture as a basement. You can check everything related to Assyrian and Mesopotamian art for your style.
As for statues Mesopotamians used to build large and massive statues:
http://www.jravnholt.dk/Fotoalbum/UN..._babylon03.jpg
Mostly they were built-in:
http://www.slowlane.net/travel/photo...esopotamia.jpg - I like these gates. Maybe they'd be useful for you.
They also prefered high statues to small ones with big bases:
http://www.theartnewspaper.com/iraqm...syrian/140.JPG
Hope this information will be useful for your project cause I like it's scale and detailedness.