civ 5 combat, civ 4 city management mod?

[ZapRowsdower]

I've never modded anything before, but how difficult would it be to come up with a reasonable approximation of Civ4 terrain output and improvements along with Civ4 building cost and functionality?

Obviously things like cottages and windmills would need to find a simpler substitute, but I'm wondering if such a mod would be at all reasonable? Perhaps we'd all just be rolling in so much gold that it would be easy mode.