How to Install & Vent Cooker Hood Via Existing Chimney Stack (Ext Wall

I need to install cooker hood above range cooker that is sited in an old chimney breast. I want the hood to be vented through the existing chimney stack as it's on an external wall. Will this need local authority building control involved? Have been advised to buy a canopy hood - is this right? I want the sides & back of the chimney clad in stainless steel (replaces existing steel that's poory installed). How do I fit hood as no cabinet (which is what canopy hoods seem to be designed to fit into)? Do I get steel plate to seal off the chimney, with cutout for hood? Any alternative ideas? Finally, what trades would do this? Builders? Sheet metal fabricators? Cooker hood installation specialists? What sort of cost could I be looking at?