Superflat or normal seed for my first megabuild?

I've been a Minecraft player for quite a while, but this is my first "megabuild". After playing Civ5, I feel inspired enough to attempt to rebuild many of the world wonders that are in the game, but on a 1 to 1 scale. The only real question I have is whether I should make the seed superflat or use a normal world.

Thoughts?

EDIT: For future reference, most of what I want to build will be on this list

http://civilization.wikia.com/wiki/List_of_wonders_in_Civ5