There is not doubt that if you want to stream videos using the laptops mentioned here, you will need a robust internet connectivity.
You can use the following standard for choosing your internet speeds for streaming
Standard Definition: 3 Megabits per second (Mbps)
High Definition: 5 Mbps
For 4k (Ultra High Definition): 25 Mbps
You can read up more about this here and also read the Netflix Resource on UHD streaming.