Hi Adrien,
In some cases pre-fab panel boards are suitable for the proposed installation, but in some instances a bespoke panel is required and a panel builder will be more adaptable with obtaining componements for the panel. For example if you go to your local bank and ask for a competative mortgage they will try and sell you one of their own “competative” products, but if you go to an independent broker they will find a suitable product after searching the whole market.
Regards
David