I wouldn't recommend using any ombré kits like the L'Oreal ombré kit, since your hair is brown. A bleach is definitely more reliable.
The brand of hair bleach you use isn't as important as the Volume. Every box of bleach you find will have a Volume ranging from 10 to 40 - this indicates the concentration of hydrogen peroxide.
For brunettes, it's important to know that you probably won't get the results you want the first time. This is because the first bleach application is likely to make your hair ginger. Your hair will only go blonde if you bleach it for a second time on top of the ginger, like I did with my hair.
So, I would recommend using a Volume 30 bleach. A lot of girls use the hair teasing method to apply the bleach for ombre, but I think that this is messy. The best way to create a natural blend from your natural colour to tje ombre is by combing the bleach into your hair. Apply some bleach to a comb, and then run this from where you want the ombre to begin. After yhis, you can apply the rest of the bleach to the ends of your hair with your hands (wearing gloves).
Leave for up to an hour. Maximum two hours. When you wash it out, your hair should be ginger. Wait a week and then apply bleach again, but this time only to the absolute ends - leaving some ginger hair at the top. Same method again (using the comb to create a blend between ginger and start of blonde) then wash out after just over an hour. This should hopefully give you a ginger and blonde ombré effect, however, bearing in mind that your hair is brown at the moment, it might take more than an hour for the bleach to work.
Also, ensure that the bleach stays wet throughout the whole setting time (reapply throughout the hour if you have to) - all dyes and bleaches become ineffective once dry.
Edit: I've just noticed that you have a slightly shorter layer of hair at the front (around your face) - apply bleach to the ends of these so they can become ginger, but don't apply bleach a second time on these (they should stay ginger not blonde)