as the airbag sensors are all that I have to worry about for wiring and they are the same as whats in my Fist now?
You will not need to run wires for seat heaters or the electric motors, so that will save you some work. If you are going to take the bottom Recaro bolstering and covers and put them on your stock Fiesta seat bottom then you will not have to worry about the seat belt switches or the passenger pressure sensor.
You can then take the Recaro seat backs and bolt them on to the Recaro wrapped Fiesta seat bottoms. Then you will have to connect the airbag wires from the seat backs (these are not airbag sensors, these are the actual airbags). These are not the same type of connector as the Fiesta airbag connectors (at least not in my swap) so you can use an adapter. Disclaimer, I do not really know if the airbags in the Recaro seat backs are the same as in the non-Recaro Fiesta seats, so even if you connect them I am not 100% sure they would deploy.
Maybe someone else can chime in here, I think most airbags work on the same type of signal so the Recaro FoST shoulder bags connected to the non-Recaro FiST wiring should work, but I'm not 100% on that.