Can someone recommend a bed?

Can't recommend a specific bed, but I know my BIL (similar weight to you) after having similar experiences - done some research and used a company that produced a custom made bed for larger individuals. I never knew such existed, but upon looking there seems to be several companies out there specialising in such areas - surely worth a look and an investment for one that will last many years?

Cotswold co

Loaf muffin top mattress. I have this in super king and it’s lush

Are you happy with your mattress?
If it is only the bed base that needs replacing then why not make a chassis using 2x2 to make the frame, and 8x4 for the flat support. A simple divan cover will hide anything that doesn't look "professional". It is just a base

getlaidbeds.co.uk

They do Good quality beds but bit costly, not sure of any other place which do similar quality cheaper.

I have this one at home

getlaidbeds.co.uk/wooden-beds/storage-beds/wooden-ottoman-storage-bed (edited)

Might be worth looking at reinforcedbeds.co.uk/