Is it possible to fit the outside air temp sensor and have it working so that it displays on the dash of a 1.2 16v sx brava.
what parts would be needed and what wiring?

it would be a real pain. you need the wing morror with the sensor and its wiring harness, and the instrument cluster from a model with air con. you would probably also need further wiring and parts such as the climate control ecu. you need to compare the wiring diagrams for your model and a model with the temp sensor to see which parts you need to add.