The specs indicate that the 600A will work fine when installed in series in the cold water supply to the cold faucet. You'll need to get the proper hardware to make the connections. If you're smart you'll allow for a graceful retreat back to the way the plumbing was if your don't like the filter or it fails or needs service. Is there a particular aspect of your water quality you don't like because these filters will only do so much.

I am adding some photos in case they are helpful to anyone. I have a "cluttered sink." ;) I am ok with it because it still looks balanced and is a large sink. It has a bridge faucet (Grohe Bridgeford) w/ side spray and a R/O cold water faucet (Newport Brass.... they match really well for different brands!) The R/O faucet was added after we moved in as we realized we needed to further purify our rural well water. We used the hole/space the air gap had used. Of course, the water softener ppl will say this is perfectly fine.... but our plumber agreed later on that it should be fine. (In some parts of the country, air gaps aren't required by code. In some they are. If we sell our house, we'll have to put the air gap back to pass inspection.) What I like about our set up is that the faucets have plenty of room to swing completely. My hubby and I can easily stand side-by-side at the sink, both using a faucet. This happens often. RE: the speed of the faucet.... the R/O faucet is quite slow. It isn't as bad as the filters you can add on to your existing faucet, but it's close. Since I'm normally only filling a glass of water, I don't mind. I got used to the speed and waiting some extra seconds. It certainly takes less time than going to the store and hauling home bottled water. :)

We have the water filter at the main sink. Not only is it closer to the glasses; it's closer to the espresso machine and tea things and to the baking center. That's convenient for making bread dough. We also find other advantages to having it at the main sink. Ours is instant hot water as well as cool. When cleaning just a pot or two, it is convenient to add some hot water from it to the tap water to get warm water for washing instead of waiting for the hot tap water to arrive (and it saves water). Someone who needs water doesn't have to disturb someone using the prep sink. For example, getting rice started while someone else preps for a stir fry.

Try the Bosch Electric Mini-Tank Water Heater Tronic 3000 T 2.5-Gallon (ES2.5) We used to use InSinkErator, but after replacing six of the units in one year, we gave up on them. Poor quality. You do not need to buy the tank unit and faucet from the same company. The connections are standardized, so you can use most any faucet with any tank.