Currently I use a Samsonite backpack for my laptops and other carry on essentials. With two laptops it can get heavy so my other bag is a spinner which allows easy "ride on top" for the backpack.

I usually place under the seat, but for overhead bin just watch bag's smallest dimension. Since mine is overstuffed it fits under seat but I may flatten the bag by shifting accessories to the top once the bag is laid flat. (Reducing the depth, usually needed under the seat but not for overheads). Other alternative is to put accessories in rolling carry on as you suggested.