@coffee might have some recommendations for you concerning this task you see in front of you.
If your looking to amass a stockpile of movies I guess there are two ways your going to do this.
1. Rip DVD's to file and store them
2. Download them from the internet.
I have a massive collection of movies and recordings that I keep on my server. Most everything I watch is recorded first using a 6 port ceton card with a comcast card in it. I can record up to 6 shows at once. Then if I really feel the need I can move them for long term storage to my server in the basement. All my recording and watching of stored movies happens on my MythTV box in the living room. I pay 10 bucks a year to support the channel and content listings.
If your going to download them from the internet then you have to take some precautions. I do not know the situation in the UK but here in the states and with comcast they will send you a warning first about downloading illegal content. If it becomes a habit then they probably will cut your service. This happened to my neighbor. I told her about Qbittorrent and she started downloading movies. She got a email warning her from comcast.
The way around such things is to join a VPN service. I recommend PIA. They are not that expensive and seem to do a good job. Now comcast can see that you are downloading but do not know what you are downloading. So, I have never received a warning from them and my neighbor doesnt either.
There are times that I want to rip a dvd for long term storage. I do this thru linux. Not all dvd's can be ripped because of the security on them. However, The vast majority can be. You can read up on it if you do a search for it.
Personally, If the movie is already available on the net then I will not waste my time ripping a dvd. I will just download it. As long as the quality is good then there is no problem.