I like Jessica Smith, I did her Piyo and it was funJessica Smith has some walking and low impact workouts on You Tube:
https://www.youtube.com/user/jessicasmithtv/featured
Another option for you might be Jenny Ford--she has some walking workouts.
https://www.youtube.com/channel/UCmev1eHpKJ7HfQyV4Tm_qBg