Hello! I am renovating three bathrooms using Ikea Gdmorgon cabinets. In each bathroom, I'd like to have a cabinet unit with sink and an adjacent cabinet unit with countertop. I have two questions;

1. Does the IKEA cabinet + IKEA countertop sit flush with the unit that has an IKEA sink? So for example, an IKEA Godmorgon/Braviken paired with Godomrgon/Tolken. I am confused because the height is different and I am not sure if the top of the sink lines up w/ the countertop to create a seamless look?

2. If I were to use non-IKEA countertop for higher quality, would I use the height/thickness of the IKEA countertop for specifications? How would I know if it would be flush w/ the sink unit?

Thank you in advance for your advice! IKEA does not really explain this well.