The simple answer is yes but..

What sort of fire do you want? Gas? wood burning? Back boiler? Best speak to a Corgi registered installer (for gas) or Hetas (for solid fuel) .  Tell them you are thinking of replacing an old fire and would like a quote and the chimney inspected for suitability. Do that before you do any bricking up of the old opening. Depending on the age, condition and the type of appliance the chimney might need to be lined.

Many fire shops will either employ a registered installer or will certainly know one. If you want to buy the fire yourself go direct to a registered installer and when he calls show them the brochure for the fire you have in mind and ask them to tell you exactly what flue kit is required. However I suspect most will probably prefer to supply and fit.