Youtube type video editing

We have a bunch of presenter videos currently just using a green screen back ground and we would like to jazz them up like the following video: https://www.youtube.com/watch?v=BrYASdWb_Ew&feature=youtu.be

We had another freelancer do something like we would like, please see this video:

https://drive.google.com/file/d/18xR3EIVQRRSJvzDuT2Ex5O0u9XAuPRpC/view?usp=sharing

. But as you can see, they haven't done a great job of the face cut out.

So we're looking for something similar, but quality work.

Please let me know if you are able to do this and interested?