What’s the best thing for my hair?

I currently have blonde ombré and I’m getting my hair dyed brown, my hair dresser said I’ll need to use shampoo and conditioner that doesn’t strip hair colour once it’s dyed, what are some good products I could use? Also what’s the best way to prep my hair before so that the colour will stick to the bleach as best as it could? She said the blonde will gradually come back through and it will need a few goes with the dye