What has amazed me most about the so-called "modern' English is all the published books out there in the market. Recently, the institute I work in has brought the new edition of a series of communication-based books called 'American English File". I think they could be a good option for you, and your students, since their latest version was just published in 2010. They are published by Oxford and I'm sure the website would give you enough hint to decide.
just browse oxford's website.