Besides some extra connectors, some extra line and a splitter for a couple of drips, I also bought a valve to place before the canisters to close them to I don't have to go to the saddle valve every time.
I also bought a pressure regulator to reduce the pressure. Figured I wanted to slow the flow down a lot and make the cartridges last longer. I also bought a pressure gauge, I think the regulator drops it to 35 psi, I put the regulator after the sediment filter so when the pressure drops I know the filter is getting clogged up.
Then finally I just used drip emitter at the end to drip 2 gallons an hour into the tank. I went overboard on some of it, more than I really needed to, but I tend to do that. All the parts I bought were-
Three canisters-
https://www.bulkreefsupply.com/brs-chloramines-upgrade-kit.html
Two carbon blocks to get started-
https://www.bulkreefsupply.com/brs-universal-carbon-block-filter-1-micron.html
A sediment filter, I ordered one from BRS, then discovered the big pack on Amazon-
https://www.bulkreefsupply.com/ge-rosave-z-depth-sediment-filter.html
https://smile.amazon.com/gp/product/B00TMIK5OM/ref=oh_aui_detailpage_o07_s01?ie=UTF8&psc=1
You'll need extra line, I like all mine to match. It is the same size as the ridged ice maker line at Home Depot-
https://www.bulkreefsupply.com/1-4-mur-lok-polyethylene-ro-tubing.html
Valve so you can change out canisters-
https://www.bulkreefsupply.com/mur-lok-ro-inline-ball-valve-push-connect.html
I used a saddle valve to connect to the water supply-
https://www.bulkreefsupply.com/self-piercing-saddle-valve-1-37241d744c96e57d29332979a23b8c5c.html
Gauge I use-
https://www.bulkreefsupply.com/air-filled-pressure-gauge-1-100-psi.html
You'll need the wrench to open the canisters-
https://www.bulkreefsupply.com/wrench-for-reverse-osmosis-canister.html
Splitter I use-
https://www.bulkreefsupply.com/mur-lok-ro-tube-divider-1-4-x-1-4-x-1-4-push-connect.html
Also chlorine/chloramines test strips to make sure water is still coming out clean-
https://www.bulkreefsupply.com/insta-test-free-total-chlorine-strips-lamotte.html
Pressure regulator-
https://smile.amazon.com/gp/product/B00MVBUJZC/ref=oh_aui_detailpage_o07_s02?ie=UTF8&psc=1
Drip emitter for 2 GPH-
https://smile.amazon.com/gp/product/B01G0YJJYW/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1
Bigger list than you probably need but thought I'd list out what I am using. Let me know if you have any questions.