Does anyone know a place to Download good maps for locations?

I have a few older ones from some D20 Modern books, but I'm starting to really repeat myself.

Just use the google.
Pick a building that looks cool and edit the damn thing.

I've turned old funeral homes into office buildings and old office buildings into corp factories.

You may give a look at the "Sprawl Sites" e-book, it comes with several generic locations like banks, fast-food, restaurants... that can be used "as-is" or as inspirations for your own plans.