Sounds like you could find some of that stuff in the mapping elements forum, like Poison suggested. Might also find some useful links in the news forum... many pros on here have linked to bundles of things for maps that they've created for sale on other sites. Not free, but the links might point you toward other sites that may have what you're after, if you can't find it here. I think I've heard them called 'miniatures' by the way, but I could well be wrong (I don't play those types of games).