How to surprise an Opeth fan ?

My boyfriend is the biggest Opeth fan (he also loves Katatonia) we love sharing music and surprise each other with new music, I would like to surprise him with something he might not know (some prog of course), Im death and trash metal and kinda new to prog (but opeth I know for few years and enjoy a lot even been on their concert). I know I can look for it myself but I'm curious about your suggestions.