I've seen it done both ways. I personally would choose to line the entire floor with the sub floor, then lay the cabinets. It may cost a few $$'s more, but it will help with lower floor soundproofing and give it a uniform look. Another consideration would be your dishwasher, which is set on the floor. If you continue your finished floor in the space where your dishwasher is installed, it will make it easier to remove if or when servicing is needed.