For your purpose a combustion calorimeter ("bomb calorimeter") is most suitable and recommended. In this type of calorimeter the food sample is burned in pure oxygen at elevated pressure and the temperature change is measured. With the known heat capacity of the "bomb" the heat of combustion is easily calculated. Good luck
No I can't, all calorimeters on the market are OK, The differences depend on your demands (mass of the sample, precision demand etc.) Please search in the internet "combustion calorimeter" contact the manufacturer tell your problem and ask them for an advice. It is always a good idea to ask them to measure a test sample for you. Good luck!