Okay so you want to go a "Bleach blonde" look. This will be different to different people. So You want to go Platinum blonde? Dark blonde all one color?
If you want to go a very light (baby blonde) platinum (almost to a white) ask your stylist to do a very heavy foil all over. It won't be a solid blonde that you are looking for the first time but it will get you closer to the look and end results will be applying a color to the roots only when you need your grow out done.
Like I said before, It is possible from what you are saying but in the long run, your stylist knows your hair and can see your hair as where I can't. You can always get a second opinion from another stylist also. Call a salon and ask for a consultation.