As Cynical Pilot said - as long as it's integrated and follows the syllabus, there is no need for it to be completed full time. I had many part time students on the 150 hour syllabus, and also a few I picked up later in their training who ended up on the 200 hour syllabus.
It is important however that the flying school is aware that this is the path you wish to proceed with and that you inform them from the beginning that you are working toward a CPL so that you can do it in line with the 150 hour syllabus and though it has been a few years since I was working on the desk/as an instructor so a bit hazy on the matter I believe those on the 150 hour course are exempt from paying GST - am I correct?
If there is no record of being enrolled in the 150 hour syllabus, you sit exams out of order or before you have certain qualifications (eg sitting certain CPL exams before having solo cross country time) you will need to continue with the 200 hour course.
Of course this could have changed, or could be changing next year with the introduction of Part 61.
But my advice would be that if you have the money available to be able to fly as regularly as you plan to, there is no reason you cannot achieve your PPL before finishing school. It would certainly allow you to achieve your CPL sooner and get out into the industry!
Good luck!
