55 gallon RO tank DIY

I am looking to expand my RO capabilities. I currently just run into 5 gallon bucks but is slow, requires constant checking and difficult if I want to do a 20-30 gallon water change. I have bought a 55 gallon brute commercial trash barrel (2 actually in case I want to eventually connect them. Looking for suggestions on a supply list for a valve and parts to drill into the bottom to quickly fill buckets. I am going to eventually put an auto shutoff RO/DI unit on it to just keep the barrel full automatically. When we buy a new house my hopes are to have a big central sump system in the basement for all the tanks and maybe run an auto top off from the RO tanks to the sump to keep it full. Does this setup seam reasonable for anyone who has done something alike? And what parts do you recommend for my base set up with the fill valve on the bottom. Aquarium sealant to help prevent leaks?
Going to build a solid lumber stand for my RO barrel tomorrow and hopefully setup barrel to start filling sunday.

 

That's awesome. Exactly what I was look for. How others have done theirs and what they have used. Since we know we are moving in the future I want to start with a simple setup and when we buy our new house worry about a salt mix tank. I just want less to rip apart and move when the time comes

 

Is it sad that part of my house hunting for our new house involves several requirements based on aquariums? :/ lol. After a year of doing things the way we have I want to eliminate some of the "work" lazy I know. I love maintaining everything. Just want to spend less time watching and carrying buckets and more time enjoying the tanks