RO/DI water has been stripped of all its ions so is agressively trying to get back to its natural "dirty" state. It eats brass and most all metals other than high grade stainless and exotic metals like titanium and tantalium.
I am using the same 23 gallon Rubbermaid containers as Heathd.hd and with the normal Spears ball valves found at HD and Lowes. been set up that way for 7 years now and still working perfect. The valves turn a little tight at first but loosen up once broken in.
When I worked in the treatment plant we used the high $$ Sch 80 ball valves pictured and they are not any better than the Spears valves for our purposes. If you want to go that route and plumbing supply house or industrial plastics vendor will have them on the shelf locally. Here is one I used a lot:
Harrington Plastics Store Finder