Rattycrat has compiled just about every map available into a "Map Pack" available to download from
here.
Included in the download is a script you can use in game to change between maps.
I would have to agree with Ratty when he said "No map I have found has 'everything', I find myself switching between different maps depending on the application. Some have boss camps, others have jack legchopper locations, etc. And this project will end, and I will consider it mission accomplished, when
someone puts together a map to kill all other maps, and we can just use that. I don't want to continue to update a growing site of lots of crappy maps, I want this to lead to one awesome map, or a set of maps from the same person, now that people can see what's out there."