You’ll need three. You’ll need building regs self-certification for the electrics, a Gas-safe engineer to cap the old supply, and a kitchen fitter to do the final installation.
I’d approach kitchen fitters first as they’re sometimes qualified to do simple electrical job like this, or will know other electricians/plumbers who can come in to do the work. You can sometimes get away without upgrading the supply to a new induction hob, depending on the circuit.
In terms of sequence of works, then the electrician and gas man will need to be on site first.
