We are planning to install a used brown quartz countertop on our bathroom vanity. We also bought two new rectangular undermount sinks on Craigslist. ( I bought both because they were very reasonably priced and I wasn't sure which one would work best.) I don't know anything about buying sinks but after measuring our cabinet, I'm not sure that either sink will fit. The inside width our our cabinet is only 20 3/4".

The first sink is a white Kohler Ladena. I think it is the bigger K2215. The inside measurements are 20 5/8" x 13 5/8". The second sink is a Decolave Classically Redefined sink. It looks almond colored to me but I think the actual color is called biscuit because it appears that this sink is only available in white or biscuit. The Decolav inside sink measurements are 18 3/8" x 12 3/8". It is difficult to accurately measure the outside of the bowls but the Kohler sink seems to be at least 20 3/4" wide. Does the top lip have to fit inside the cabinet or just the bowl? I thought that the lip could rest on top of the cabinet with just the bowl fitting between the cabinet but that may not be correct. I tried to research it but found conflicting advice on this issue.

We will be pulling the cabinet out to paint it white. The countertop is 21" deep right now. Would that be enough depth to allow for a faucet hole? If not, perhaps we could pull the cabinet out farther to make room for the faucet?

Which color sink looks better with the counter? I've always heard that off white is best with brown. The toilet is bright white but it is separated from the sink by a pocket door and can't be seen at the same time as the sink.

The first two photos are of the Decolav sink.

The next two are the Kohler Ladena sink.