We had a gas fired Rayburn that also did the heating. It was great for a year, kept the kitchen nice and toasty. But we replaced it with a modern boiler and it's much warmer, and way more controllable. Not necessarily cheaper as it's on a lot more.
We also replaced a lot of the pipework too around the house, put newer radiators in (cleaned out all the sludge too and new boiler has a magna cleanse to keep it working well). Maybe you want to put your boiler in a better location than the kitchen.
Plenty of decent modern range cookers to occupy the space or, if you're going for a modern look, use the space completely differently and get normal ovens and a hob.
We also replaced a lot of the pipework too around the house, put newer radiators in (cleaned out all the sludge too and new boiler has a magna cleanse to keep it working well). Maybe you want to put your boiler in a better location than the kitchen.
Plenty of decent modern range cookers to occupy the space or, if you're going for a modern look, use the space completely differently and get normal ovens and a hob.