The granite counter in our hose was already at least 10 years old when we moved in, and I had no idea it was supposed to be sealed until I had been using it for at least 15 years. I still haven’t. It does not stain, despite hard use with all kinds of potentially staining things such as blueberry juice when making jam, turmeric, acidic liquids of all types (I used to make lots of pickles). I have been known to clean something stuck on it with a brillo pad. 
The only place it shows anything is immediately around the cooktop. I had to replace the original one, and the new one has a slightly smaller footprint. I think the slight darkening is probably due to 30 or so years of cooking grease penetrating under the metal.
I don’t know what kind of granite it is, but it is as hard as a rock! It is fairly light color, a very natural-looking speckled combo of shades of gray with black.
BTW, on the double vs single bowl sink, you CAN have a sink with two big bowls, if you are willing to sacrifice the counterspace.