Need some help with a reverse osmosis machine

So i have this like 8 year old reverse osmosis machine from everpure and it looks really expensive, and its hardly ever been used it never worked right with who ever set it up in the kitchen.

So ive been trying to get it working and have no idea where to start.

So then since i have some money i was thinking ill just buy a new one less hassel more trustworthy... but now my predicament is which one to buy for my garden, as well as for drinking. And how will i hook it up to the garden hose faucet i have conveniently next to my plants.

Thanks for any help 8D