Good Songs for "the things they carried" trailer?

I have an english project where we have to make a two minute long trailer for a movie about the book we read, "The Things They Carried," by Tim O'Brien. The book is about war. I was wondering if anyone knew a few (4-5) good songs that go together well that are sort of saddish. They only catch to this (and the reason I cannot decide on songs) is that we are only allowed to use up to 30 seconds of each song due to copyright infringement laws. So if anyone can help by including the 30 seconds of the songs that are best to use that would be great as well. Thanks a bunch in advance :D