74 Dart Swinger new stereo system

Looking to install a new stereo and speakers in my sons 74 Dart Swinger daily driver. He doesn't want to modify the dash and disturb the original look. Would like to install the stereo and speakers now as a Christmas gift, but need it to have the availability for him to add an amp and sub woofer later on his own. Does anyone have any experience with either using a retro look stereo that fits his old radio space, or a hideaway stereo system?
Thank
Mark