Rhett Barnwell and Seraphim Music have a couple of CD’s, but they are not only harp and cello. One is celtic harp, cello and soprano, and the other is celtic harp, cello and other instruments and voices. You could email them and ask for some clarification on how much other instrumentation is included. Rhett is a very nice person to work with.
Yeah, they are mostly seen or heard in classical songs. I had this one chance to watch harp and cello instructors played together and it sounded so great. Never thought these two instruments would sound good together.