a battle i gave, with a really awesome map/picture :P

[Gran Capitán]

Yes that is the best answer.

With the KS mod you can get some additional maps based on SoW GB free expansions and random maps made by the community.
There is also the GB game maps, but in order to play those you must have the game and paid expansions.

But I don't think the KS mod maps will work with the sandbox campaign.