If you want videos of penholders playing SP forehand, inverted backhand, you can find some among these playlists.
https://www.youtube.com/user/oneredfish2046/playlists?sort=dd&shelf_id=0&view=1
Some are single-sided, but others use RPB, such as:
Jiang Haiyang
Zheng Jiaqi
Sun Chen
Liu Guoliang
Sun Jian
Li Kwun Nga
Ono Shiho
Finding videos of shakehand player playing SP forehand is difficult. For the ultimate in SP FH shakehand you should also look for Johnny Huang, in my opinion. He's perhaps the best SP forehand shakehander there ever was, IMHO, although he plays SP on BH as well.
Other SP forehand shakehanders you should look for are:
Teng Yi
Li Jiawei
Shen Janfei
Zhenqi Barthel (I think she SP forehand. Not 100% though)
Wan Yuan (German junior player. Very exciting to watch)
Good luck