The first video is using a heavier more powerful motor and those replacement forks and dropouts are really beefed up. As you say a lot of wiring mess plus I don't like that battery on the seat post.
The second video is where you fit a kit into your existing forks. The wiring and battery is much more subtle being in the bag. This motor is less powerful 180W but adequate and I have used a similar motor for the last 3 years and 6000 miles pretty much daily, without any problems with motor or frame
As stated I am not a retailer of any of the systems listed and have no affiliation with them, but I do buy all the component parts direct from China to make up my own kits. I have converted a few family and friends bikes but pretty much at cost of the parts only.
Regards
Jerry