yes and no, theres more to it.
get the ecu first, it will have 1 or 2 codes on it, OFAC or OFAB, the engine loom that connects to the ecu must be the right one for the code on the ecu, something you have to take the word of, of the seller if on ebay, but the difference between the OFAC and OFAB is a few pin locations which can be moved, or you can conver the xr2i engine loom to suit the ecu.

also the injectprs you use must be right for the ecu running them, i forget the word im looking for but some injectors will not work with the FRST ecus, like cossie injecotres for example, they cannot ne used with FRST ECU so check the injectors you have will work, i would say but i am unsure tbh mate.

you will also need the map sensor to suit the ecu, again OFAC ior ofac and OFAB of ofab, but cossie one can be used if using ofab.

and fianly you will also need the turbo ACT (actual charge temp) sensor, if you dont, it will run like toss