You should be posting this in a builders/brickwork forum as it's the support you are removing for the chimney stack and the rest of the house that may be a problem. And the arrangement to disperse the loads that should be the main concern.
You can fit basket style fires in this way shouldn't be a problem, but as i say it's the building work that needs to be planned and thought through first. With specialist structural advice.
You will probably have to get a professional out to have a look, as there's many house styles. They will not be able to offer advice without seeing the house.
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