theKalash
All you need is a VPN, connect to the UK and you can make an account on channel4.com and watch everything there.
With some fiddeling around you can even download the videos straight from their website.
I hardly download from them, so I don't have an automated way.
What I do is use ublock origin to look at the network calls, find the media link and then use curl to download it.
Your post is lacking information. What do you WANT?
Do you really care about the quality and want 4k if possible? Are you trying to scale media amount? In that case, 4k remuxes will need an insane amout of disk space compared to 1080p. Do you need to support multiple people streaming, so transcoding and bandwidth is relevant?
Without knowing what you want to achieve it's impossible to make that choice.
Well, they have a point.