The biggest issue that I encounter with similar customers is that they are convinced that the ONLY easy to use player is the iPod or whatever they are currently using. They absolutely do not want to learn anything new. tomciara's suggestion of loaning a system might be helpful, but that will still run into the problem of needing to learn something new.

A lot of "easy" is personal preference. I still remember my encounter with an original iPod at a customer site. I had heard how easy they were to use. I tinkered with it for a few minutes. I thought that the user interface was incredibly hard to navigate. I don't think that I have touched one since. I had an iPod touch for a while, only because it supported Sonos. It was not my favorite user interface.