That's beautiful, kimmers! I've done one of these blocks which is on a little sampler my DD has in her room, it looks great as a whole quilt! As for the quilting, if you really want to make the hearts puffy, I would outline quilt AND echo at 1/4". I'm currently quilting a bed quilt with appliquéd hearts like that and they really POP! I've got wool batting in as well which is really fluffy.
K x