Thanks for the advise Teetee!Dunno if you have this option.... I used to bolt my RO machine to one end of a plank, prop it up in the shower. Unscrew the shower head and the RO machine pipe screwed on right nice.... no extra fittings required.
Filled up a 60L flexitank reservoir and used a cheap aquarium pump connected to a short length of hosepipe to fill up buckets.
This is the unit I’ve been using… might be similar to what you have. I could just unscrew the one in the garage and move it into the house but like the option of placing the whole bucket in the sink to avoid any flooding from over filling.