make you countertop wider than standard. there is no reason the width has to match the cabinets underneath. the cabinets are just not mounted flush with the walls.
you are just pulling them out a few inches.
you are buying work-space , not walk-space
depending on the cabinets you get , they can be made deeper. get the best "roll out " sheaves for the
lower cabinets you can afford
what you are buy is then counter top space. make sure the ' splash ' counter top is at least 3 " 4 is better. oddly the splash part is relatively expensive.