I agree with Shawn. If he really wants four channel capacity, and particularly if he is less then fully adept at taping and/or computers, anything else would make life really difficult. He could try a portable mixer, and mixing on the fly, but you get that one try, and that is it, for better or worse. A used modded R-4 would, at least at the beginnng, obviate the need for anything else, other than mics, cables, stand and the usual equipment. He is going to have to learn how to use a computer, and some of the usual software under any circumstances, so just teach him Audacity or Samplitude or another relatively easy and cheap, multi-track program.