As far as I know, you can only upgrade Ram and Hard drives in Toshiba's laptops. If you want a laptop you can upgrade CPU's and GPU's then you need to look at a pre 2012 Alienware laptop (used) or if you are looking new, it needs to be a laptop that uses Clevo motherboards. brands include Sager, High end MSI laptops, Origin PC laptops, and Eurocom laptops.
Those are CPU and GPU upgradeable and the only laptops I purchase. No one but the manfacturer's like BGA.