A very useful tool is to take aluminum foil and shape it into the shape and with the dimensions of the faucet you are considering. Do two of them if you are looking at two faucets. If your sink is installed, hold the aluminum foil model over it, or even tape it down, to get an idea of how it will look and fit. If your sink is not installed, cut out cardboard (from a flattened box works nicely) in the dimensions of the sink you will have. These visuals are really helpful. I also did similar for drawer pulls when I couldn't decide on pull sizes.

BTW, your "30 x 18" sink is a good-size sink. Many on this forum have gone smaller due to lack of space. That size sink will look fine with a good-sized faucet. A prep faucet may have too short of a reach and not look in proportion. The "reach" is the distance measured from the center of the faucet base horizontally to the water stream. It is specified on all faucets' spec drawings. Yes, you will have a pull-out hose, but the faucet reach is crucial to how it will look in your sink. The hose length really isn't as important. The faucet reach length also has an effect on your comfort at the sink. If the faucet water stream is too close to the back of the sink, you will be having to reach your hands farther to rinse things. Even a couple inches makes a difference on your back.

I hadn't thought about me having to reach further for the water flow - that's an excellent point.

Which Kalia are you looking at? I have the Diver and thought it was huge when I first got it. You really do get used to the visual size though. :)

My sister said the same thing -- she thought her faucet was huge when she first got it, but now she thinks it looks properly proportioned to her sink. I'm looking at a Neris Diver or Elito Surfer -- they look good on spec, but I haven't actually been out to see them in person and put my hands on them. I like to know how it will fit in my hand when I'm using it, if I can. I'm not sure why the Elito Surfer looks so different from the Elito Diver, but I like one much more than the other.

Comparing the specs and images, I liked the Surfer much better, but once I saw them both in person, I preferred the Diver. I think part of it was the feel of the pull down. Have you found a place that has these faucets on display? If not, try Dupont Plumbing on Eglinton. They had both when I bought mine last year. (I'm assuming you're in Toronto, Canada)

Yes, I'm in Toronto Canada, and I have Dupont Plumbing on my list of places to visit. Do you have the Neris Diver, or the Elito Diver?

That is a fairly large sink so the faucet won't dwarf it. Get a faucet with the maximum flow that you can get for your area.

I have the Elito Diver.

We bought a Kohler Vinnata 10 years ago when we remodeled our home. There is a full size version and a prep sink version. We opted for the smaller prep sink because like you, I thought the full size version was way too big. Our sink is a Shaw's farmhouse. I know its 30" long, but I can't remember how wide it is....18" sounds about right. It's a plenty big sink.

Anyway, I wish we had gone with the bigger faucet. Our problem has been the amount of splashing behind the sink, specifically around the faucet itself. There is always water pooled there and I attribute it to the fact the faucet doesn't reach far enough into the sink. I will say other than the splashing problem, the faucet has been great. Water flow is fine and the hose reaches everywhere it needs to.

We are building a new house now and we will definitely be putting in a larger faucet with a deeper reach.

So, I liked what I saw and handled, particularly with the Elito Surfer, but specs show it needs a pinch more than 2.5 inches behind it to work the water lever to the "hot" side. That sounds like a lot of space - probably more than I would have.....It's about what I have now, but the sink I'd like (a 30" wide Kraus single bowl undermount) is a little bit larger than the 30" wide double bowl top mount that I have now. I'll discuss it with my KD, but I might have to readjust my thinking.

Double check with your KD. The amount of space that I need behind my Diver (which has the same specs as the Surfer) is under 2 inches. I think the specs that you are looking at measure the distance from the middle of the faucet base, not the back.

Yes, I measured what I have now to the center of my current faucet. Still, of course, I'll check with her too.

If you really love the faucet, have you considered mounting the control at the front rather than at the side? I know there have been a lot of folks here that prefer that orientation.

I put a very nice Moen prep faucet on my small laundry sink, and while it looks good, it is way underpowered. Were it on my kitchen sink, I'd be unhappy. Where it is, it is a reasonable compromise.

Regarding mounting a faucet control on the front, I have that configuration. The beauty of it is that your wet hands will drip into the sink, not onto your countertop. Think how often you turn the faucet off and on with drippy hands while working at the sink. Some people (me) do it a lot, others perhaps not so much?