Years ago I worked in the admin offices for Golden Charter, their way of working is to set up the plan with a local funeral director. Any monies paid are put into some sort of trust account that cannot be touched until death, this protects if the local funeral director goes belly up. This was the practice 10ish years ago and from what I’ve read it’s still the same.
It’s certainly worth getting multiple quotes, the level of inflation in the funeral industry is unbelievable, so the sooner you get an agreed price the better value you will get.