I use this backpack for my tools. I highly recommend it. I use some individual small tool zippered bags to organize some of the smaller or more uniquely shaped tools. Plus the light is helpful and it folds open flat. Can be found cheaper from other sellers than the linked page.
https://goclc.com/products/Work-Gear-CLC-Tech-Gear/L255
For parts, rubbers, switches etc. I use these Milwaukee boxes. They lock together and the removeable bins are great.