We ADORE our Everpure water chiller. Ours was installed about 7 years ago and we love it! It does take up room and does create heat so make sure to have good ventilation or a wide enough space for it. We burned out 2 units until DH installed a small computer fan to exhaust the space into the next cab.

it's basically an air conditioner, you've seen em hundreds of times - they've just been covered up by the housings of the water fountains. Elkay makes a few and so does Insinkerator (ISE)for residential use. Here is a link that might be useful: water chiller

I would like a chilled water from a small faucet in our prep sink. Similar to many instant hot setups but for cold water. We have an RO system in the attic above the kitchen and I would like to install a water chiller near it and basically get the filtered water chilled via a faucet at the prep sink. Please recommend a chilled water system that will work with a RO? I am guessing it will need a bladder and lined faucets similar to the instant hot systems. Any recommendations/ ideas?

I purchased a RO system a while ago for my previous house and didn't have any problems. It was pretty easy to install too (less than 1 hr). The filters in the new units look to be easier to change, though I don't have any experience with those.